NOEA 2011 International Symposium on Nitrogen Oxides Emission Abatement Book of Abstracts Edited by J. BARTYZEL, P. KORNELAK, M. NAJBAR 4-7 September 2011 ZAKOPANE, Poland Symposium finansed by WND-POIG. 01. 01. 02-12-112/09 co-financed by the European Regional Development Fund under the Innovative Economy Operational Programme 2007-2013 ISBN 978-83-233-3249-7 Wydawnictwo Uniwersytetu Jagiellońskiego Redakcja: ul. Michałowskiego 9/2, 31-126 Kraków tel. 12-631-18-81, 12-631-18-82, fax 12-631-18-83 Dystrybucja: tel. 12-631-01-97, tel. /fax 12-631-01-98 tel. kom. 506-006-674, e-mail: sprzedaz@wuj. pl CONTENTS PREFACE...........................................................................9 Maria Skłodowska-Curic - a heritage of the 19th and the legacy to the 21 st century B. PETELENZ..................................................................11 Maria Sktodowska-Curie in philately, numismatics and medallic art J. BARTKE.....................................................................13 Maria Sktodowska-Curie as a role model for scientists A. RAFALSKA-ŁASOCHA...........................................................15 Treatment of off-gases containing NOX by electron beam A. G. CHMIELEWSKI, J. LICKI, A. PAWELEC, Z. ZIMEK, Y. SUN, S. WITMAN.........17 Plasma assisled-deNOₓ catalysis G. DJEGA-MARIADASSOU.........................................................19 Performance of the plasma treatment catalyst compared with a classical thermal on alumina catalysts: an approach to NOX abatement M. FOIX, C. GUYON, M. TATOULIAN, P. Da COSTA.................................21 State-of-the-art nitrogen oxide removal from off-gases of stationary sources by ammonia M. A. BUZANOWSKI.............................................................23 Simultaneous NO reduction and soot oxidation on transition metal oxide catalysts M. NAJBAR, E. PAŁKOWSKA, J. DUTKIEWICZ, I. NAZARCZUK, L. LITYŃSKA-DOBRZYŃSKA, E. BIELAŃSKA, A. WESEŁUCHA-BIRCZYŃSKA. W. IASOCHA, J. CAMRA, M. KOZICKI...................25 Modelling of structured reactor based on wire gauzes and zeolite catalyst for ammonia reduction of NOX from biogas turbines P. JODŁOWSKI, J. OCHOŃSKA, D. Mc CLYMONT, B. GIL, A. KOŁODZIEJ, S. KOŁACZKOWSKI, J. ŁOJEWSKA..........................27 Copper exchanged zeolite in structured reactor based on wire gauzes for ammonia reduction of nitrogen oxides from biogas turbines J. OCHOŃSKA, A. KNAPIK, D. Me CLYMONT, A. ROGULSKA, P. JODŁOWSKI, B. GIL W MAKOWSKI, A. KOŁODZIEJ, S. KOŁACZKOWSKI, J. ŁOJEWSKA ..................................29 NOx removal from stationary sources by selective catalytic reduction A. E. PALOMARES..............................................................31 Modified clay minerals as effective catalysts of the DeNOₓ process L. CHMIELARZ.................................................................33 Modified carbonaceous materials in DeNOₓ reaction T. GRZYBEK, J. KLINIK, M. MOTAK, B. SAMOJEDEN................................37 HC SCR as alternative process for NOX abatement in stationary and mobile sources P. Da COSTA..................................................................41 3 Effect of Cl and C2 organic reducing agents on selective catalytic reduction of NO on FeSiBEA and CoSiBEA zeolites J. JANAS, W ROJEK, S. DŹWIGAJ...................................................43 DeNOₓ assisted by hydrocarbons A. AISSAT, D. COURCOT, S. SIFFERT..............................................45 Influence of the crystallite size of nobel metals on the course of the DENOX reaction D. NAZIMEK, W ĆWIKŁA-BUNDYRA....................................................47 Structural-functional design of catalysts for gas emissions purification from nitrogen (I), (II) oxides S. ORLYK, S. SOLOVIEV, T. BOICHUK, P. KIRIENKO..................................49 Strategy of NOX reduction for the Diesel engines of light passenger cars J. -M. TRICHARD.................................................................53 Selective Catalytic Reduction of NOX by diesel fuel: plasma-assisted HC/SCR system B. K. CHO, J. -H. LEE, C. C. CRELLIN, K. OLSON, D. L HILDEN, M. K. KIM, P. S. KIM, I. HEO, I. -S. NAM...........................55 Catalytic behavior of combined LNT/SCR systems P. FORZATTI, L. LlETTl, L CASTOLDI, R. BONZI, S. MORANDI, G. GHIOTTI, S. DŹWIGAJ..............................................59 Effect of thermal aging on surface morphology and performances of commercial Lean NOX Traps D. ADOUANE, P. Da COSTA, P. DARCY..............................................61 Modelling of N₂O formation during the regeneration of NOX storage catalyst Ś. BARTOVA, P. KOCI, M. MAREK, J. PIHL, J. -S. CHOI, W PARTRIDGE................63 NO reduction by H₂ on Rh-based catalyst for Natural Gas vehicles: Study of active sites by operando IR spectroscopy S. CARRE, Y. RENEME, F. DHAINAUT, C. DUJARDIN, P. GRANGER.......................67 Controlling the surface dispersion of bao nano-domains on catalytic NOX storage materials via TiO₂ anchoring sites and improvement of sulfur poisoning tolerance E. ÓZENSOY, G. SEDA $ENTURK, E. VOVK...........................................69 NOx reduction and methane oxidation over mesoporous silica supported palladium J. BASSIL, A. AIBARAZ1, P. Da COSTA, M. BOUTROS ................................71 Design of the Catalysts for the Removal of Diesel Soot and NOX Z. ZHAO.........................................................................75 Catalytic filters for the simultaneous removal of soot and NOX: influence of the alumina precursor on monolith washcoating and catalytic activity M. E. GALVEZ, S. ASCASO, 1. TOBIAS, R. MOLINER, M. J. LAZARO....................77 Silver-based catalysts for NOX SCR with ethanol: a mechanistic study on Ag/ZSM-5 and Ag/AI₂O₃ A. WESTERMANN, R. BARTOLOMEU, B. AZAMBRE, R. BERTOLO, C. HENRIQUES, A. KOCH, P. Da COSTA, M. F. RIBEIRO..............................81 4 Investigation of Cs-Cu/ZrO₂ systems for simultaneous NOX reduction and carbonaceous particles oxidation A. AISSAT, D. COURCOT, S. SIFFERT.............................................83 Effect of water on NO decomposition over Cu-ZSM5 based catalysts G. LANDI, L LISI, R. P1RONE, G. RUSSO, M. TORTORELLI..........................87 Hysteresis effect study on Diesel Oxidation Catalyst for a better efficiency of SCR systems A. MANIGRASSO, N. FOUCHAL, P. DARCY, P. Da COSTA..............................89 lx>w temperature N₂O decomposition over nano oxide catalysts A. KOTARBA, G. MANIAK, P. STELMACHOWSKI, W PISKORZ, F. ZASADA, Z. SOJKA.......91 The influence of structural promolors on the activity of iron oxide based catalyst for N₂O decomposition P. KOWALIK, K. STOLECKI, K. MICHALSKA, J. KRUK, M. KONKOL.....................93 Stoichiometric and non-sloichiometric Perovskite-based catalysts for the catalytic decomposition of N₂O from nitric acid plants Y. WU, X. NI, P. GRANGER, C. DUJARDIN.........................................95 N₂O catalytic decomposition - from laboratory experiment to industry reaktor L. OBALOVA, K. JIRATOVA, F. KOMANDA...........................................97 The application of metallic iron for N₂O reduction al higher temperature and oxygen presence J. LASEK, B. GRADOŃ...........................................................99 Copper ionic pairs as active sites in N₂O decomposition on CuOₓ/CeO₂ catalysts A. ADAMSKI, W. ZAJĄC, F. ZASADA, Z. SOJKA....................................101 Dual role of surface nitrate species formed during NOX activation on supported oxometallic TM1 clusters 4. ADAMSKI, M. FIUK, M. TARACH, P. ZAPAŁA, B. GIL, Z. SOJKA..................107 Comparison between Cs-Cu/ZrO₂ and Cs-Co/Zr0₂ catalysts for NOX reduction in the presence of toluene A. AISSAT, D. COURCOT, S. SIFFERT............................................111 On the influence of exhaust gas composition for the selective reduction of NOX over Fe/ZSM-5 catalyst D. ADOUANE, J. STARCK, P. Da COSTA, X. JEANDEL...............................115 DRIFTS-MS studies of NO reduction and NH₃ oxidation over V-O-V catalyst B. AZAMBRE, J. BANAŚ, M. NAJBAR.............................................117 SEM -EDS studies of transition metal catalysts for NO decomposition E. BIELAŃSKA, M. ZIMOWSKA, I. NAZARCZUK, M. KOZICKI, M. NAJBAR...............119 XPS studies of Ni-Cr-Fe oxide catalysts for NO decomposition J. CAMRA, J. DUTKIEWICZ M. KOZICKI, M. NAJBAR................................121 Acid-activated vermiculites as catalysts of the DeNOₓ process L. CHMIELARZ, M. WOJCIECHOWSKA, M. RUTKOWSKA, A. WĘGRZYN, A. ADAMSKI, B. DUDEK, R. DZIEMBAJ, A. MATUSIEWICZ, M. MICHALIK..................................................123 Is Hydrogen the main NOX reducing agent at low temperature for a CNG 3-way catalysts? M. ADAMOWSKA, S. CAPELA, M. SALAUN, L. GAGNEPAIN, P. Da COSTA...............127 5 Influence of the ion exchanged metal (Cu, Co, Ni and Mn) on the selective catalytic reduction of NO over mordenite and ferierite W. ĆWIKŁA-BUNDYRA..........................................................131 Structural studies and physicochemical properties of new molybdenum peroxocomplexes with nicotinic acid A. DOBIJA, W. NITEK, W ŁASOCHA.............................................135 Effect of soot on NO decomposition in O₂ and SO₂ presence over Ni-Cr-Fe oxide catalysts J. DUTKIEWICZ, S. JAN1GA, I. NAZARCZUK, M. KOZICKI, P. KORNELAK, M. NAJBAR.137 Surface, structural and morphological characterization of nanocrystalline ceria-zirconia mixed oxides upon thermal aging /. DOBROSZ-GÓMEZ, M. A. GÓMEZ-GARCIA, M. 1. SZYNKOWSKA, I. KOCEMBA, J. M. RYNKOWSKI................................................139 Nanostructured Co-Ce-0 systems for catalytic decomposition of N₂O R. DZIEMBAJ, M. M. ZA1TZ, M. RUTKOWSKA, M. MOLENDA, L CHMIELARZ............141 Membrane reactor for ammonia decomposition - design guides M. A. GÓMEZ-GARCIA, I. DOBROSZ-GÓMEZ, J. FONTALVO, J. M. RYNKOWSKI.........143 IR studies of the coadsorption of CO and electron donor molecules on Cu⁺ sites in CuZSM-5 zeolite K. GÓRA-MAREK.............................................................147 The simultaneous SCR of N₂O and NOX on Co-Na-MOR using CH₄ alone as the reducing agent M. C. CAMPA, V. INDOVINA, D. PIETROGIACOMI.................................149 In situ FT-IR spectroscopic investigation of gold supported on lungstated zirconia as DeNOₓ catalyst M. KANTCHEVA, M. MILANOVA..................................................151 Co-Mn-Al mixed oxide supported on TiO₂ for N₂O decomposition K. KARASKOVA, Ż. CHROMCAKOVA, S. STUDENTOVA, L. OBALOVA, K. JIRATOVA.......155 Photocatalytic decomposition of N₂O on Ag-TiO₂ K. KOCI', S. KREjdKOVA, Z. ŁACNY, O. SOLCOVA, L OBALOVA...................159 Effect of V concentration in niobium-rich V-O-Nb/anatase catalysts on their activity in ammonia assisted DENOX P. KORNELAK, A. BIAŁAS, D. RASIŃSKA, J. CAMRA, W ŁASOCHA, W ZHANG, D. SU, A. WESEŁUCHA-BIRCZYŃSKA, M. NAJBAR.........................163 Alloying effect on NO direct decomposition over high surface area Rh/AI₂O₃ catalysts A. PIETRASZEK, P. Da COSTA, P. KORNELAK, B. AZAMBRE, L. ZENBOURY, M. NAJBAR.165 NO decomposition over Mo-V oxide bronzes P. KORNELAK, M. ŁABANOWSKA, W MACYK, M. TOBĄ, I. NAZARCZUK, M. NAJBAR.......167 Effect of surface potassium doping and NOX addition on catalytic activity of iron and cobalt spinels in soot combustion P. LEGUTKO, P. STELMACHOWSKI, A. KOTARBA, Z. SOJKA.........................169 TEM studies of transition metal oxide catalysts for NO decomposition L. LITYŃSKA-DOBRZYŃSKA, K. STAN, M. KOZICKI, M. NAJBAR....................171 6 DRIFT study of dcNOₓ reaction over Cu/CeZrO₂ catalyst A. ŁAMACZ, 4. KRZTOŃ, G. DJEGA-MARIADASSOU..................................173 XRD study of oxide Ni-Fe-Cr catalysts for NO decomposition W. ŁASOCHA, A. RAFALSKA-ŁASOCHA, I. NAZARCZUK, M. NAJBAR....................175 Modified Synthetic Spinels as Catalysts for Low Temperature deN₂O G. MANIAK, F. ZASADA, W PISKORZ, P. STELMACHOWSKI, A KOTARBA, Z. SOJKA.......177 The use of DESONOX type catalysts to remove nitrogen oxides during coal combustion A. MARCEWICZ-KUBA...........................................................179 Multi-step TPSR/QMS technique to study kinetics of NO, SR with ammonia D. Mc CLYMONT,, J. OCHOŃSKA, S. KOŁACZKOWSKI, J. ŁOTEWSKA...................181 N₂O formation during lean NOX reduction by hydrocarbons over a conventional DOC D. MRAĆEK, S. BARTOVA, F. PLAT, P. KOCI, M. MAREK..........................183 Effect of O₂, SO₂ and H₂O on NO decomposition over Ni-Cr-Fe oxide catalysts J. DUTKIEWICZ, S. JANIGA, I. NAZARCZUK, M. KOZICKI, P. KORNELAK, M. NAJBAR...187 NOX uptake and storage properties of BaOₓ/Pt( 111) model catalyst: influence of Ba coverage, surface morphology and stoichiometry E. OZENSOY, E. VOVK, E. EMMEZ..............................................189 Selective Catalytic Reduction of NOX by C₂H₅OH over Ag/Al₂O3/cordierite N. POPOVYCH, P. KIRIENKO, S. SOLOVIEV.......................................191 Study of the interaction of NOX and NH₃ with the surface of copper and nickel catalysts supported on ceria-zirconia by FT-IR spectroscopy M. RADLIK, A. ŁAMACZ, A. KRZTOŃ, W. TUREK..................................193 Catalytic reduction of NO by CO over FeₓSiBEA catalysts I. HNAT, I. KOCEMBA, J. RYNKOWSKI, S. DŹWIGAJ...............................195 Preparation and characterization ofTiO₂ based plasma sprayed catalytic coatings for NOX abatement V SNAPKAUSKIENE, V. VALINCIUS...............................................197 MgF₂-MgO system as a potential support for NiO catalysts for NOX reduction by propene M. ZIELIŃSKI, I. TOMSKA-FORALEWSKA, M. PIETROWSKI, M. WOJCIECHOWSKA.........201 Raman spectroscopic studies of the oxide Ni-Fe-Cr catalysts for NO decomposition A. WESEŁUCHA-BIRCZYŃSKA, M. KOZICKI, M. NAJBAR..............................205 Metal-supported sulfated ceria-zirconia catalysts for the SCR of NOX by ethanol: performances and mechanisms A. WESTERMANN, B. AZAMBRE, A. KOCH..........................................207 INDEX............................................................................211 7 PREFACE Interest in nitrogen oxides emission abatement has been steadily growing for years both in academic and industrial research. NOEA 2011 lies also in this field. The symposium is a continuation of the annual seminars organized by Jagiellonian Universityand Marie Curie-Sklodowska University since 1994 and followed by International Symposiaon Air Pollution Abatement (2003), Air Pollution Abatement Catalysis (2005) and Air and Water Pollution Abatement (2007). This year the organizer - Faculty of Chemistry of Jagiellonian University - invitedthe research community to discuss the following topics, at the both global and molecular level: • NO removal from off-gases of stationary sources of emission, • NO reduction in exhaust gases of mobile sources of emission, • Simultaneous NO reduction and particles' oxidation, • N₂O removal. A small introductory session is devoted to hundred anniversary of Maria Sklodowska-Curie Nobel Prize in the field of chemistry. 38 oral (6 plenary lectures, 14 keynote lectures and 18 communications) as well as 39 poster presentations covering all these subjects form the mainstream of the symposium. Internationally renowned researchers were invited to give overview of various important areas: • Dr. Mark A. Buzanowski, On the state-of-the-art of NO removal from off-gases of stationary sources by ammonia, • Prof. Lucjan Chmielarz, Modified clay minerals as effective catalysts of the DeNOx process, • Prof. Andrzej G. Chmielewski, Treatment of off-gases containing NOx by electron beam, • Prof. Patrick Da Costa, HC SCR as alternative process for NOx abatement in stationary nd mobile sources, • Prof. Gerald Djega-Mariadassou, Plasma assisted-deNOx catalysis, • DSc Stanislaw Dźwigaj, Effect of C| and C₂ organic reducing agents on selective catalytic reduction of NO on FeSiBEA and CoSiBEA zeolites, • Prof. Pio Forzatti, Catalytic behavior of combined LNT/SCR systems, • Prof. Teresa Grzybek, Modified carbonaceous materials in DeNOx reaction, • Prof. Andrzej Kotarba, Low temperature N₂O decomposition over Nano Oxide Catalysts, • Prof. Dobiesław Nazimek, Influence of the crystallite size of nobel metals on the course of the DENOX reaction, • Prof. Lucie Obalova, N₂O catalytic decomposition - from laboratory experiment to industry reactor, • Prof. Svitlana Orlyk, Structural-functional design of catalysts for gas emissions purification from nitrogen(l), (II) oxides, • Prof. Antonio Eduardo Palomares, NOX removal from stationary sources by selective catalytic reduction, • Prof. Stephane Siffert, DeNOx assisted by hydrocarbons, • Prof. Jean-Michel Trichard, NOx emission reduction: Passenger car manufacturer point of view, • Prof. Zhen Zhao, Design of catalysts for emissions abatement of diesel soot and NOx, The organisers hope that this symposium will promote further discussion on the important issues of environmental protection and lead to closer cooperation of researchers interested in this field. The NOEA Symposium is organised in framework of the POIG project "Innovative catalysts for direct NO decomposition on the base of oxide bronzes Organising Committee 9 NOEA2011 Zakopane 4-7 September 2011 POI Maria Skłodowska-Curie - a heritage of the 19th and the legacy to the 21st century B. PETELENZ¹ ¹ The Henryk Niewodniczański institute of Nuclear Physics, Polish Academy of Sciences, 152 Radzikowskiego St., 31-342 Kraków, Poland, e-mail: barbara.petelenz@ifj.edu.pl The year 2011 has been proclaimed by the IUPAC and UNESCO as the International Year of Chemistry. This coincides with the centenary of the Nobel Prize in Chemistry 1911, awarded to ‘Marie Curie, nće Skłodowska, in recognition of the discovery of polonium and radium, isolation of radium, and further studies on this remarkable element’. So far, Marie Curie has been the only woman awarded with two Nobel Prizes. In 1903, Marie and Pierre Curie shared the Nobel Prize in Physics with Antoine Henri Becquerel, the discoverer of radioactivity. The pioneering studies on radioactivity were the subject of the Marie Curie’s doctorate research. Their consequences went far beyond the extension of the periodic table by two new elements. A chain of discoveries, made by Marie Curie and her contemporary scientists, revolutionized the existing views on the structure of Matter and initiated the development of modem physics and chemistry, as well as nuclear technologies. The intellectual and emotional heritage of Maria Skłodowska-Curie was the 19th century positivism which, generally, means a philosophy of sciences, and in partitioned Poland it meant also a political program of national resistance, focused on creating a material infrastructure and educating the public. Both senses were conspicuous in Maria’s research methods, in her teaching, in the organization of the Radium Institutes, and in her war effort. She truly believed in the positivist idea that the Science should serve the Humanity. Radium started to serve the Humanity promptly. Discovered in 1898, it was first used for radiation therapy in 1901. Very shortly, Pierre and Marie Curie realized that benefits from its applications are dramatically entangled with threats. Aware of this duality, Marie Curie always taught that applied science must be based firmly on the fundamental research. In the 21s¹ century, it is worth remembering too. 11 NOEA 2011 Zakopane 4-7 September 2011 KOI Maria Skłodowska-Curie in philately, numismatics and medallic art J. BARTKE¹ ¹ The Henryk Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences 152 Radzikowskiego St., 31-342 Kraków, Poland Philately and numismatics is not just stamp or coin collecting: numismatics is an auxilliary branch of human history, and philately is on its way towards a similar status. Also, stamps and coins, items which are issued in large quantities, offer wide publicity and promotion for a person or an event, and it is this aspect that will be explored in this presentation. Maria Skłodowska-Curie (MSC) has been featured on about one hundred postage stamps from many countries (on half of them she appears together with her husband Pierre Curie), and also on other philatelic items such as postal stationery or special cancellations. We will show some more interesting specimens, with emphasis on the ones presenting the “chemical aspects” of her activity, related to her discoveries of the new chemical elements polonium and radium, and to her Nobel Prize in chemistry awarded in 1911. The earliest stamp featuring MSC was issued in Turkey in 1935 on the occasion of the International Women's Congress in Istanbul. Some issues from years 1938-1949 carried an extra charge for the anticancer campaign. Many stamps were issued at various MSC anniversaries, but she appeared also in the category of “Nobel Prize winners” or simply among “famous people”. The effigy of MSC can also be found on Polish and French banknotes and coins, which will be presented as well. Medallic art is of a somewhat different character. Commemorative medals, usually created in a limited number by renowned artists, are small pieces of art, paying tribute to a famous person or to a remarkable event The first medal featuring MSC was issued in Poland as early as 1934 (shortly after her death), and the first French medal in 1938 to commemorate the 40lh anniversary of the discovery of radium. The medal created in the USA in 1966 for Poland's Millenium features MSC together with Mieszko I, the founder of the Polish state, and Nicolaus Copernicus, as the three most important personalities in one thousand years of Polish history. An interesting Czechoslovak medal of 1967 evokes Jachymov Valley (St. Joachimsthal) as the place from which the uranium ore for the Curies came. 13 NOEA2011 Zakopane 4-7 September 2011 K02 Maria Skłodowska-Curie as a role model for scientists A. RAFALSKA-ŁASOCHA¹ ¹ Faculty of Chemistry, Jagiellonian University, 3 Ingardena St., 30-060 Krakow, Poland, e-mail: rafalska @ chemia, uj. edu.pl Maria Skłodowska (1867-1934) spent her youth in Poland, but during and after studies she lived and worked in France. Coincidence of many circumstances caused that she had two fatherlands. Her discoveries to the benefit of the mankind, however, made her a national of the whole world. In 1893, Maria Skłodowska obtained the bachelor degree in physics at Sorbonne with the first honour position and in 1894 the bachelor degree in mathematics with second honour position. Then she relumed to Poland to search for a suitable job. Very soon she realized that there was not a suitable position for her. Prof. August Witkowski, who was always willing to help her, was not even able to offer her the assistant position at his Chair of Physics at the Jagiellonian University in Krakow. In Poland which was in those times divided between three invaders: Austria, Russia and Prussia, she would have had to be excluded from the academic life without which she would not have had the opportunity to apply her knowledge and skills and satisfy her justified ambitions. This is why she decided to come back to France where in 1895 she married Pierre Curie and worked with him in his lab. After discovery of new chemical elements Maria and Pierre worked in a very hard conditions but were always cautious about the privatization of research. At the beginning of the career, they deliberately did not patent their technique for purifying radium so others would be able to conduct research on it more easily. When later, thanks to women of America, Maria received the gram of radium for research, she insisted on giving control of the radium to the University of Paris upon her death. Her co-workers retained full access for research purposes but the radium itself passed into the public’s hands. As a scientist and a human being Maria Skłodowska Curie was and still is a worldwide hero. She was invited for the Solvay Conferences, conferred honoris causa doctorates by many universities and apart from two Nobel Prizes she was awarded many other scientific honors. However, for this modest personality, the matters of science were the most important. When she was asked to write a few words on the occasion of the tenth anniversary of regaining independence by Poland, she wrote words which are regarded as her scientific testament: -To develop scientific laboratories which Pasteur called „sacred shrines of mankind", ■to take care of those who work for science craving knowledge in order to attain workers for the future, -to create conditions for the innate talents and precious gifts might be realized and serve for the idea means lead the society through the way of development of power both spiritual and material. These and other values represented by Maria Sklodowska-Curie are still up-to date for the people all over the world. Not only for Poles is she a symbol of personality of the highest moral value and highest scientific qualifications. After her death, Albert Einstein in the telegram of sympathy to her family expressed it as follows: “Now, when the life of such an outstanding personality as Mrs Curie was ended we mustn't only limit our memories about her to that what the fruits of her work have given the humanity. The moral values of the exceptional personality have perhaps a deeper meaning for the given generation and for the whole course of the history then the intellectual achievements only. “ 15 NOEA2011 Zakopane 4-7 September 2011 P02 Treatment of off-gases containing NOX by electron beam A. G. CHMIELEWSKI¹³, J. LICKI², A. PAWELEC*, Z. ZIMEK¹, Y. SUN¹, S. WITMAN¹ ¹ Institute of Nuclear Chemistry and Technology, Warsaw, Poland ² Institute of Atomic Energy, Świerk, Poland ³ Warsaw University of Technology, Department of chemical and Process Engineering, Warsaw, Poland Electron beam flue gas treatment is well developed flue gas treatment technology for simultaneous SOx and NOx removal and generating usable product - fertilizer being a mixture of ammonium sulfate and nitrate. The biggest industrial plant has been built in EPS Pomorzany, Szczecin where it treats 270 000 Nm³/h and a power of accelerator installed exceed 1 MW. These one of the cold plasma technologies successfully applied in industry. Beside the gas purification for coal fired boilers, the process is well suitable for high sulfur oil fired boilers as well. The recent studies have illustrated possibility of this technology application for volatile, non methane, organic pollutants and mercury treatment. The main consumption of the energy is devoted to the NOx removal, high efficiency SOx removal is achieved at low energy deposition dose. Therefore different methods for energy consumption reduction are searched for. One of the method is applying of the gas flow patterns at double gas irradiation dose, which ensure good distribution of energy distribution field. Other method is applying a special scavengers to enhance radical driven reactions in the gaseous phase. The developments of the technology and reducing of the energy consumption may lead to the most difficult applications as a huge Diesel engine exhaust gases treatment, which the problem is not solved up to now. The plasma processes including electron beam generated plasmas are being developed in the frame of BalticNet - PlasTEP project towards the broader technology applications. 17 NOEA2011 Zakopane 4-7 September 2011 K03 Plasma assisted-deNOₓ catalysis G. D.IEGA-MARIADASSOU¹² Universite Pierre et Marie Curie, UPMC Paris 6, Laboratoire Reactivite de Surface, UMR CNRS 7609, 4 place Jussieu, Case 178 Tour 54-55, 75252 Paris Cedex 05, France ² Centrum Materiałów Polimerowych i Węglowych PAN, 41-800 Zabrze, ul. Curie-Sklodowskiej 34, Poland Role of non-thermal plasma Starting from a review of literature, - more particularly from the numerous papers already published by the Society of Automotive Engineers (SAE) and comparing to chemistry of non-thermal plasma and to molecular models of deN()ₓ process, the present key-note will demonstrate that a non-thermal plasma can substitute two functions (NO to NO₂, and NO₂ mild HC oxidation to CₓHyOz oxygenates) of the general three-lunction deNOₓ catalysis over supported metal cations (Mⁿ⁺). The main feature is that efficient catalysts are only working in a given range of temperature where the three functions turn over simultaneously, whereas non-thermal plasma is working (2 functions) in the full range of temperature 11-4] (Fig. I). Figure I. Comparison of Catalysts activity and that of non-thermal plasma vs. Temperature The preceding model can help to understand how the plasma assisted-deNOₓ catalysis is working [1-4]. The three-function model of deNO„ Three-way and dcN()ₓ catalysis follow the same general catalytic sequence [5-8]: NO decomposes on the active site (Mⁿ⁺), leading to N₂ and O(ads), and the reaction is then controlled by the oxygen scavenging process through a reaction between the adsorbed reductant and O(ads). Depending on the catalytic process (TWC or deNOₓ), the nature of the active site varies (M° and Mⁿ⁺), as well as the reductant. 19 NOEA201I Zakopane 4-7 September 2011 In both M° and Mⁿ⁺ cases, the system needs a reductant to “regenerate” the active site: CO in the case of a stoichiometric mixture (TWC), and an activated hydrocarbon (HC —> CₓHyOz) or the initial HC in lean conditions (deNOₓ). In all cases, NO dissociation or “global reduction” to N₂ (Function 3 in dcNOₓ model over metal cations) goes through: • the adsorption of, at least, two NO molecules; • the dissociation of 2NO leaving 2O(ads); • the necessity, for a reductant, to scavenge the 2O(ads), for recovering the free sites and permitting the catalytic cycle to tum over. The very important and interesting point in both TWC and deNOₓ processes is the simultaneous activation of NO(ads) and reduclant(ads) as evidenced by transient temperature programmed reactions, leading to the ‘assisted’ reduction of NO by this reductant (Fig. I). There is never a direct interaction between NO and the reductant, but rather two main steps: decomposition of NO and oxygen-scavenging by the reductant. Main objectives The aim of the key-note concerns: (i) the state of the art of the non-thermal plasma/catalyst coupling, summarizing the global main results (activation of hydrocarbons, speciation of stable species at the outlet of the plasma reactor, active catalytic materials...), (ii) the short presentation of the three-function model of deNOₓ, (iii) the speciation of stabilized molecules produced during the plasma/gas phase interaction. A typical gas mixture will be: decane - toluene - propene - propane - NO - H₂O - O₂ - Ar mixture. Non-Thermal Plasma Assisted Catalytic NOX Remediation from a lean Model Exhaust will be studied: experimental device; on-line analysis of reaction products, effect of energy deposition, concept of composite catalyst, reaction in the presence of exhaust gases. [1] O. Gorce, H. Jurado, C. Thomas, G. Djega-Mariadassou, A. Khacef, J-M. Cormier, J-M. Pouvesle, G. Blanchard, S. Calvo, Y. Lendresse, “Non-Thermal Plasma Assisted Catalytic NOx Remediation from a Lean Model Exhaust”, (2001) SAE Technical Paper series, 2001-01-3508, Non-thermal plasma emission control systems (SP-1639), SAE IntemationakThe Engineering Society for Advancing Mobility Land, Sea, Air Space (2001) [2] F. Baudin, P. Da Costa, C. Thomas, S. Calvo, Y. Lendresse, S. Schneider, F. Delacroix, G. Plassat, G. Djega-Mariadassou, “NOx reduction over CeO₂-ZrO₂ supported iridium catalyst in the presence of propanol”, (2004) Topics in Catal., 30-31, pp. 97-102 [3] G. Djega-Mariadassou, M. Berger, O. Gorce, J. W. Park, H. Pemot, C. Potvin, C. Thomas, P. Da Costa, “Chapter 5. A three-function model reaction for designing deNOx catalysts”, (2007) Studies in Surface Science and Catalysis, 171, pp. 145-173 [4] G. Djega-Mariadassou, F. Baudin, A. Khacef, P. Da Costa, “Chapter 4. NOx abatement by plasmacatalysis”, (2010) In: “Plasma-catalytic processes: Activation of molecules and environmental applications”, VasileParvulescu and Dr. Monica Magureanu Eds., John Wiley & Sons Ltd, submitted for publication [5] G. Djega-Mariadassou, Catal. Today 90 (2004). 27 [6] G. Djega-Mariadassou, M. Boudart, J. of Catal., 216 (2003). 89 [7] G. Djega-Mariadassou, F. Fajardie, J.-F. Tempere, J.-M. Manoli, O. Touret, G. Blanchard, J. of Mol. Catal. A: Chemical 161 (2000). 179 [8] M. Boudart, G. Djega-Mariadassou, in Cinetique des Reactions enCatalyse Heterogene, Masson, Paris, 1982, M. Boudart, G. Djega-Mariadassou, in “Kinetics of Heterogeneous Catalytic Reactions”, Princeton, University Press, Princeton, NJ, 1984 20 NOEA2011 Zakopane 4-7 September 2011 CO I Performance of the plasma treatment catalyst compared with a classical thermal on alumina catalysts: an approach to NOX abatement M. FOIXU, C. GUYON², M. TATOULIAN², P. Da COSTA** ¹ Universite Pierre et Marie Curie, Paris 6, Laboratoire de Reactivite de Surface - CNRS UMR 7197, 4 Place Jussieu, 75252 Paris 05, France, e-mail: marjorie.foix@etu.upmc.fr ² Ecole Nationale Superieure de Chimie Paris - Chimie ParisTech, Laboratoire “Genie des Procedes Plasmas et Traitement de Surface”, 11 rue P. et M. Curie, 75231 Paris cedex 03, e-mail: cedric.guyon@enscp.fr *Dr. P. Da Costa, tel: + 33 1 44 27 55 12, e-mail: patrick.da_costa@upmc.fr Catalysis is the enabling technology in a large number of processes for the provision of clean energy, and for pollution abatement. Heterogeneous catalysis occurs at the interface between a gas or liquid and a solid catalytic surface; the surface of a catalytically active solid provides an energy landscape which enhances reactivity. The use of plasma systems in catalysis is now well established (Brockhaus and al. [ I ], Xia and al. [2J, Karches and al. [3, 4]). Plasma treatments, in low pressure systems, have been already studied, in order to try to replace the thermal calcinations of catalysts. On the other hand, fluidized bed reactors offer the possibility to perform homogenous pre-treatments and have the additional advantage of excellent heat transfer rales between the gas and catalysts particles (Jafari and al. [5]) Thus, the combination of a plasma pre-treatment, carried out in a fluidized bed reactor, is expected to modify the catalytic properties of the prepared materials (Xia and al. [2]). The aim of this work is the comparative study of the activation of an alumina catalyst with both conventional calcination and a plasma-based system, in order to evaluate if the plasma treatment in a low pressure fluidized bed reactor is efficient to replace thermal calcination. Concerning the plasma process, the role of the plasma electrical discharge type, as well as the power density, was studied. The characterization of the catalysts, in order to understand the influence of plasma treatment on catalytic performances, is continuously in research. This comparison with “classical calcination" under air at different temperature was studied in order to evaluate eventual catalytic advantages of the plasma treatments. The catalyst is Ag (2.5wt.%)/y-Al2O₃ spheres, it was prepared by an excess impregnation method with a solution of silver nitrate (AgNO₃). Then, the excess of solution was evaporated at 60°C under reduced pressure. Finally, the catalyst were dried, prior to the two different activation processes: (i) calcination under air flow at 500°C for 2 h (10°C.min‘l) in a fix-bed reactor or (ii) plasma treatment in a fluidized bed reactor, with a discharge microwave. In this last process, the impregnated powders were fluidized by an Ar gas or a mixture of Ar/O₂ gas passing through a porous glass plate, the diameter sieved 600 pm in order to obtain a homogeneous fluidization. Thermogravimetric analyses (TGA) and derivative of loss of mass versus the time thermogram (TGD) were performed from Room Temperature (RT) up to 800°C in industrial air (100 cm’.min , 30 mg of catalyst). In order to have a better understanding of the effect of the plasma activation, TGD were performed on three samples: (i) untreated and (ii) all plasma treated catalyst by M.W and (iii) calcined samples. The TGD curve shows exothermic peaks in the temperature range 200-550°C whereas the weight loss observed between 210°C and 500°C corresponds to loss of NO₃ ligands. The purpose of the various treatments is to eliminate nitrates absorbed on the surface of catalysts to obtain a better catalytic activity. The TGD results, in the Figure la., indicate that calcination at 550°C has totally eliminated the ligands. 21 NOEA 2011 Zakopane 4-7 September 2011 Figure la. : TGD analysis of 2.5% silver on y-AfiOj spheres after various temperature of calcination : (X) 500°C-2h, (0) 400°C-2h, (A) 300°C-2h (D) 200°C-2h (O) 100°C-2h (») without treatment. Heating rate: IO°C/min, carrier gas: air, final temperature: 800°C Figure lb. : TGD analysis of 2.5% silver on y-Al₂O< spheres as a function of different microwave plasma treatments at various powers : (D) M.W-500Watts, (K) M.W-800Watts. And (X) calcination (500°C-2h), (•) without treatment. Heating rate: 10°C/min, carrier gas: air, final temperature: 800°C In the Figure lb., we analyzed the various samples treated by microwave plasma, we followed the effect of the processing power plasma on the decomposition of nitrates. We notice that when the power increases to 800 Watts, it remains little of nitrate on the surface of catalyst. The increase in the power M.W plasma has a positive influence on the decomposition of nitrates, the less there are nitrates which desorbed. The plasma treatment with microwave at 500 Watts can be associated with a calcination of 400°C, and at 800 Watts, we admit that it has the same effect than a calcination at 500°C. During the study we also checked this effect on another support, zeolite. The results confirm those observed on this support presented. We also tested various catalysts treated by plasma and by calcination in order to compare their catalytic activity to NOX abatement in mobile sources. 11 ] A. Brockhaus, D. Korzec, F. Werner, Y. Yuan, J. Engemann, Surf. Coat. Technol. 74-75, (1995) 431 [2] W. Xia, O.F.-K. Schluter, C. Liang, M.W.E. van den Berg, M. Guraya, M. Muhler, Catal. Today 102-103,(2005)34 [3] M. Karches, M. Morstein, P. Rudolf von Rohr, R.L. Pozzo, J.L. Giombi, M.A. Baltanas, Catal. Today 72, (2002) 267 [4] M. Karches, Ch. Bayer, Ph. Rudolf von Rohr, Surf. Coat. Technol. 116-119, (1999) 879 [5] R. Jafari. M.Tatoulian, W. Morscheidt, F. Arefi-Khonsari, React. Fund. Polym. 66, (2006) 1757 22 NOEA20I1 Zakopane 4-7 September 2011 P03 State-of-the-art nitrogen oxide removal from off-gases of stationary sources by ammonia M.A. BUZANOWSKI¹ ¹ Peerless Mfg. Co., Dallas, TX, USA Although selective catalytic reduction (SCR) of NOX is presently a mature technology, new design applications and stricter performance requirements present significant challenges and an urgent need for innovative technology development. This article discusses the state-ofthe-art design of commercial ammonia-based SCR systems designed for stationary sources. Particular attention is given to controlling NOx and ammonia slip emissions at ultra-low concentrations, new generation of exhaust systems for simple cycle power plants, improved ammonia injection grids, control systems designed for non-steady state operations, mathematical modeling of SCR systems designed for power plants and SCR catalyst poisoning. Ammonia, or its precursor, is needed to reduce NO to innocuous nitrogen and water. One method of injecting ammonia into a flue gas flow utilizes an external ammonia vaporization system in which liquid ammonia (either in anhydrous or aqueous state) is vaporized in a vaporizer, utilizing hot air or flue gas, and then routed to a distnbution/injection grid for injection into flue gas at the location upstream of an SCR catalyst. A new arrangement of vaporizers used for efficient ammonia generation! 1] is compared for different SCR process configurations. Further, this article presents recent efforts on improving the functionality of the ammonia injection grid (AIG)[2J. Computational and experimental studies performed on the AIG resulted in significant increases in the turbulence mixing between the injected ammonia and the exhaust flue gas. Improved mixing is instrumental to maximize catalyst performance, extend catalyst operating life, optimize catalyst volume, decrease system pressure drop, minimize reagent use and ammonia slip and reduce the overall size of the SCR system. Different arrangements of the AIGs[3],[4] developed to reduce deviations of the NH-/NO, ratio, temperature and flue gas flow are compared with conventional designs. Considering control systems, many exhaust systems that use SCR technology for controlling emissions are designed to operate at the steady-state of the underlying combustion process. The facilities for which such exhaust systems are used typically operate in a steadystate condition. Therefore, the control schemes arc designed for the times at which the systems are operating most. One of the problems in the current control schemes for SCR processes is how to handle transient, non-steady-state conditions, e.g., start-up, shut-down, heavy-loading and unloading. In these transient conditions, the operating conditions cannot be assumed to be the same as in steady-state. Therefore, the SCR system will generally not operate as designed or will not achieve the expected steady-state performance as designed within a tight time tolerance. The steady-state SCR process operates optimally when there is a unitary molar relationship between the input NOx and the injected ammonia concentration. If there is an imbalance of this molar relationship and locally, more ammonia than NOx is supplied, ammonia slip will be present. An imbalance is typical in actual operation of SCR systems. Therefore, ammonia slip is usually assumed to be present in such systems. It should be noted that, during startup transitions, the SCR process experiences continuous non-slcady-slate operation. The startup condition itself is a transient state or condition in the operation of the underlying process. However, the non-steady-state conditions that occur during startup, or most other transient states, are continuous. These transient startup conditions include parameters, such as low exhaust gas temperature, insufficient catalyst volume, abnormal levels of pollutants, and the rapid rate of change of these operating parameters, all play a role in the dynamics and effectiveness of the SCR process during such non-sleady-slate operations. New control technique has been proposed to maximize NOx removal efficiency during transient operations[5]. 23 NOEA 2011 Zakopane 4-7 September 2011 An SCR system, when designed for a simple cycle turbine, presents a significant calculation and modeling challenge due to its compact design and stringent performance requirements. In particular, uniform flue gas velocity profiles, required by environmental catalysts installed in the ductwork of this system, must be met. Custom flow devices optimized for the turbine SCR systems and ductwork are required. This article discusses possible steps taken to ductwork internals. Mal-distribution (non uniformity) in the velocity profile within a high efficiency SCR system is one of design considerations. With a specified velocity profile, high and low efficiency retrofits are compared. It is demonstrated that, while the slight mal-distribution in the velocity profile may significantly impact the performance of a high efficiency retrofit, it may be unnoticeable for low efficiency retrofits. Finally, this paper discusses a new compact exhaust system and efficient arrangement of the tempering air system for simple cycle power plants[6]. The proposed system includes transitioning hot exhaust flue gas into pre-oxidation section of the exhaust system, passing hot exhaust gas through the oxidation catalyst for the CO emissions control, injecting tempering air stream into the post-oxidation section of the exhaust system, and passing cooled flue gas through the reduction catalyst for the NOx emissions control. The resultant benefit of this newly designed process|6] is a more effective use of catalysts and a smaller exhaust footprint. [1] M.A. Buzanowski, G. Smith, T. Shippy, Systems and methods for liquid vaporizers and operations thereof, US Patent Appl. US 20100029053 [2] M.A. Buzanowski, P.J. Burlage, D.Z. Fadda, Reagent injection grid, US Patent 7,383,850, also Fluid mixing apparatus with injection lance, European Patent Appl. EP2248577 and EP1681089 [3] M.A. Buzanowski, Control for ammonia slip in selective catalytic reduction, US Patent 7,166,262 [4] M.A. Buzanowski, Ammonia distribution grid for selective catalytic reduction (SCR) system, US Patent Appl. US200040057888 [5] M.A. Buzanowski, S.P. McMenamin, T. Shippy, Controlling ammonia flow in a selective catalytic reduction system during transient non-steady-state conditions, US Patent Appl. US20101001201 [6] M.A. Buzanowski, S.P. McMenamin, Integrated exhaust gas cooling system and method, US Patent Appl. US20110158876 24 NOEA2011 Zakopane 4-7 September 2011 K04 Simultaneous NO reduction and soot oxidation on transition metal oxide catalysts M, NAJBAR¹, E. PAŁKOWSKA¹, J. DUTKIEWICZ¹, I. NAZARCZUK¹, L. LITYŃSKA-DOBRZYŃSKA², E. BIELAŃSKA³, A. WESEŁUCHA-BIRCZYŃSKA¹, W. ŁASOCHA¹, J. CAMRA¹, M. KOZICKI¹ ¹ Faculty of Chemistry, Jagiellonian University, 3 Ingardena St., 30-060 Krakow, Poland, e-mail: mnajbar@chemia, uj. edu.pl ² Institute of Metallurgy and Materials Science Polish Academy of Sciences, 30-059 Cracow, 25 Reymonta St., Poland ³ Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, 8 Niezapominajek St., 30-329 Kraków, Poland Direct NO decomposition is the most desirable method to remove NOX from exhausts because the reaction is thermodynamically favorable and does not need any reducer. The activity of the numerous catalysts in this reaction was checked. The precious metals [I] zeolites containing transition metal cations [2], transition metal oxides [3], transition metal oxides promoted by alkali or alkaline earth metal [4] and perovskites [5], were found to be effective. It is well known that the direct NO decomposition is strongly diminished by an excess of oxygen present in off gases of the stationary sources of emission [6] as well as in exhaust of the Diesel engines [2], SO₂ and H₂O present in off-gases also affect catalyst activity in the direct NO decomposition [6]. The effect of such ingredients as hydrocarbons and CO is always considered to be beneficial. Soot particles are another dangerous air pollutant. The interest of the direct decomposition of both, NO and soot, o the transition metal oxide catalysts [7-9] is still growing. Carbon is considered to be a real catalyst and transition metal oxide to be active in dissociative O₂ adsorption. CC(O) surface complexes are formed on carbon surface by oxidation with O₂ or NO₂, independently on the presence of metal oxide. They decompose above 525K, yielding carbon oxides and free active sites. The role of the transition metal oxide is to transfer atomic oxygen to the soot surface and, thus, to enhance the CC(O) concentration. Iron containing oxides were found to be effective catalysts in the direct NO and soot conversion [9], In this presentation special attention will be given to the results obtained with the use of a Ee ₂O₃ - NiFe₂O₄ biphasic catalyst formed on the acid-resistant austenitic steel supports during their thermoprogrammed oxidation. Publication co-financed by the European Regional Development Fund under the Innovate Economy Operational Programme 2007-2013, POIG.OI.01.02-12-112/09 project. [ 1 ] D.D. Miller, S.S.C. Chuang, J.Phys. Chem. C 113 (2009) 14963, and references therein. [2] A.M. de Oliveira, I.Costilla, C. Gioia, I.M. Baibich, V.T. da Silva, S.B.C. Pergher, Catal. Lett. 136 (2010)185, and references therein. [3] SJ. Huang, A.B. Walters, M.A. Vanice, J. Catal. 192 (2000) 29, and references therein. [4] W.-J. Hong, S. Iwamoto, S. Hosokawa, K. Wada, H. Kanai, M. Inoue, J.Catal. 277 (2011) 208, and references therein. [5] J.J.Zhu, A. Thomas, Appl.Catal. B:Environ. 92 (2009) 225, and references therein. [6] R. Zhu, M. Guo, E Ouyang, Acta Phys. Chim. Sin. 24 (2008) 909, and references therein. [7] V. V. Lissianski, V. M. Zamansky, P. M. Maly, M. S. Sheldon, Combust. Flame 125:1310 (2001), and references therein. [8] R. Zhu, M. Guo, F. Ouyang, Catal. Today 139 (2008) 146, and references therein. 25 NOEA2011 Zakopane 4-7 September 2011 [9] D. Reichert, H. Bockhom, S. Kureti, Applied Catalysis B: Environmental 80 (2008) 248, and references therein. NOEA 2011 Zakopane 4-7 September 2011 C02 Modelling of structured reactor based on wire gauzes and zeolite catalyst for ammonia reduction of NOX from biogas turbines P. JODŁOWSKI¹, J. OCHOŃSKA¹³, D. Mc CLYMONT⁴, B. GIL¹, A. KOŁODZIEJ²³, S. KOŁACZKOWSKI⁴, J. ŁOJEWSKA¹ ¹ Faculty of Chemistry, Jagiellonian University, 3 Ingardena St., 30-060 Kraków, Poland ² Institute of Chemical Engineering of the Polish Academy of Sciences, 5 Bałtycka St., 44-100 Gliwice, Poland ³ Faculty of Civil Engineering, Opole University of Technology, 48 Katowicka St, 45-061 Opole, Poland ⁴ Department of Chemical Engineering, University of Bath, Claverton Down, Bath BA2 7AY, UK The current technological means for cleaning exhaust gases from gas turbines are based on two consecutively-working converters: the first for NOX reduction and the second for VOC combustion. However, they suffer from several major drawbacks, the most important of which are: the size of the system (more than 10 m long) and catalysts based on noble metals, both of which greatly increase the costs of the installations. The solution for the first problem is the application of short channel structures as reactor fillers, and for the second - the search for catalytic active nanostructures. The aim of the paper is to design the wire gauze based structured reactor with the Cu²⁺ exchanged zeolite Y. This part of the study is devoted to modeling the mass transport of reactants through the assumed structures of wire gauzes. The structured catalytic reactors propose in this study expand the idea of monoliths, a successful widespread solution for vehicle exhaust removal, towards microstructures of short channels used as reactor fillers. The main advantage of structured catalytic reactors over the monoliths is that they show substantially higher mass and heat transport coefficients with reasonable pressure drop within the reactor [1-4], This is due to the fact that short channels of the elaborated geometry prevent laminar flow and facilitates reactants mixing, in contrast to long capillary channels of monoliths in which laminar flow fully develops. In this study the reactor composed of a stack of 47 wire gauzes was used for modelling. The reactor length was 0.1 m, inlet temperature 573 K, and NO concentration 3000 ppm of a flow rate 2.66 m/s. The hydraulic diameter of the mesh was 3.29-1 O'⁴ m. The reaction kinetics (power type kinetic equation) was derived from the results of catalytic tests for NO reduction with NH₃ in grandientless reactor. The reaction tests and the methods of preparation of the catalysts together with the physicochemical analyses are presented in the accompanying paper [5]. The reaction was assumed to be of a first order for the oxygen excess on the catalyst surface. The reactor model was based on 4 balance equations between the gas phase, catalyst surface and bulk .The mass transfer equation was obtained using the idea and the solutions presented by Kołodziej et al. [4] for the heat transport which was then transferred using Chilton Colburn analogy. The expansion of the previous approach was to include temperature as a variable in solving the balance equations which was hoped to refine the model considered before. The exemplary results of the modeling are presented in Figure 1 for the kinetic data obtained from the literature [6] (kᵢₙf= 7.45 • IO⁹ m/s, Ea=85.9 kj/mol). 27 NOE A 2011 Zakopane 4-7 September 2011 Figure 1. Comparison of modeling mass and heat transfer results for the wire gauze reactor (L= 0.1 m, 4>= 0.1 tn) and the monolith (L= 0.1 m, SiBEA zeolites, respectively, is evidenced by DR UV-vis, XPS and TPR. These zeolites are much more active in SCR of NO by C₂ reducing agent (ethanol and ethylene) than by C| reducing agent (methanol and methane). In Figure I we show, as an example, the NO conversion and N₂ selectivity in SCR of NO by different reducing agents on Coo₇SiBEA zeolite. These results show that catalytic activity of Coo.₇SiBEA zeolite strongly depends on the kind of organic compound use as reducing agent. The catalytic activity are similar in the presence of ethanol and ethylene, with selectivity toward N₂ exceeding 90 % for NO conversion from 30 to 55 % in the temperature range of 550-750 K and is much lower in the presence of methanol and methane with selectivity toward N₂ about 15 - 20 % for NO conversion from 10 to 20 %. A comparison of the NO conversion values in the SCR and NO oxidation reaction (without reducing agents) reveals that the activity in (he SCR reaction on both CoojSiBEA and Fe^SiBEA catalysts was higher than in the oxidation reaction. 43 NOEA 2011 Zakopane 4-7 September 2011 Figure I. NO conversion and N: selectivity in SCR of NO by methane, methanol, ethylene and ethanol on Coₗₗ ₇SiBEA and Fe₀,ySiBEA catalysts. A comparison of the NO conversion values in the SCR and NO oxidation reaction (without reducing agents) reveals that the activity in the SCR reaction on both Co₀₇SiBEA and Feo.₉SiBEA catalysts was higher than in the oxidation reaction. In conclusion, CoojSiBEA and Fe₍₎<)SiBEA zeolites containing only isolated tetrahedral Co(II) and Fe(IlI) are very active catalysts in the SCR of NO by ethanol and ethylene. In contrast, both zeolites are much less active in the SCR of NO by methanol and methane. It is probably due to the formation of different kinds of the reaction intermediates in the presence of C and C₂ reducing agents. [ 1 ] J. Janas, T. Machcj, J. Gurgul, R.P. Socha, M. Che, S. Dźwigaj, Appl. Catal. B 75 (2007) 239 [2] J. Janas, J. Gurgul, R.P. Socha, T. Shishido, M. Che, S. Dźwigaj, Appl. Catal. B 91 (2009) 113 [3] S. Dźwigaj, M.J. Peltre, P. Massiani, A. Davidson, M. Che, T. Sen. S. Sivasanker, Chem. Commun. (1998)87 [4] S. Dźwigaj, P. Massiani, A. Davidson, M. Che, J. Mol. Catal. 155 (2000) 169 [5] M. Anpo, S. Dźwigaj, M. Che, Adv. Catal. 52 (2009) 1 44 NOEA2011 Zakopane 4-7 September 2011 K08 DeNOₓ assisted by hydrocarbons A. AISSAT¹,², D. COURCOT¹’², S. SIFFERT¹,² ¹ Univ Lille Nord de France, F-59000 Lille, France ² ULCO, UCEIV, F-59140 Dunkerque, France, siffert@univ-littoral.fr, Tel.: +33-328658256 (S. Siffert) Large quantities of pollutants to the environment are released from the combustion of biomass and fossil fuels. Among these contaminants are the nitrogen oxides (NOX) which are the source of severe environmental problems. Research in the Held of NOX abatement has grown significantly in the last two decades. The general trend has been to develop new catalysts with complex materials in order to meet the stringent environmental regulations. Nowadays two main methods for the removal of NOX from emission gases are employed: the selective catalytic reduction of NOX with NH₃ (SCR) which is applied for stationary sources such as power plants and the three ways catalyst (TWC) used for mobile sources such as automobiles. In spite of the intense research, these are only partial solutions and include serious drawbacks. Alternatively selective catalytic reduction of NOX using hydrocarbons as reductant (HC-SCR) is currently attracting a great deal of interest. The aim of this review study is to gain knowledge on the selective catalytic reduction of NOX with hydrocarbons with the final goal to contribute to the development of suitable catalysts for NOX abatement. This review discusses briefly about the different sources and the emission levels of NOX, their influence on the environment and public health, their regulation, the approaches for their removal and the state of the art with respect to catalytic solutions for their removal is reviewed. Emphasis is placed on the selective catalytic reduction of NOX using hydrocarbons. Selective catalytic reduction of NOX in the presence of hydrocarbons Due to the drawback concerning NH₃-SCR, as the escaping in the exhaust and its transportation and storage, SCR of NOX by hydrocarbons is believed to be the most promising way to eliminate nitrogen oxide. The main advantage of the corresponding reaction is the use of a gas mixture very similar to that found in exhausts [1], In this review, several parameters of the SCR of NOX studied in literature are explored: the types of solids used in this reaction (metal ion-exchanged zeolite, supported metals, supported metal oxides) by exploiting also the nature of the active phase used, the catalytic stability of the materials and the mechanisms. For illustration, the first catalyst that was found to have a good hydrocarbon NOX reduction capability in oxygen rich conditions was Cu/ZSM-5 [2-4], They showed that the catalytic activity of Cu-ZSM-5 could be greatly enhanced by small amounts of hydrocarbons in the presence of excess oxygen. This reaction has been extensively studied over different cation exchanged zeolites [5] and over different base oxides (A1₂O₃, TiO₂, ZrO₂, MgO) and these oxides promoted by Co, Ni, Cu, Fe etc. [6], However, many of these catalysts are deactivated in presence of water vapour [1], Forwards, another system Ag/y-AI₂O₃ catalyst was found to be active for HC-SCR [7,8] but much higher temperatures are required. The presence of a small amount of hydrogen in the feed improved the catalytic activity significantly [9], H₂ promotes the NO, reduction over Ag/y-AI₂O₃ catalysts when using a range of lower alkanes and alkenes and higher alkanes [10] as reductants. Silver has also been used in zeolites for HC-SCR of NOX with various reducing agents [11-14], Recently, Aissat et al. [15] studied to the role of toluene but also the presence of carbonaceous particles on the NOx reduction. A maximum of NOX reduction was also found during light off curve of hydrocarbon oxidation [15,16]. 45 NOEA 2011 Zakopane 4-7 September 2011 In conclusion, the interest of the scientific community for this topic is reflected by the number of patents and contributions in the literature. [1] V.I. Parvulescu, P. Grange, B. Delmon, Catal. Today 46 (1998) 233 [2] M. Iwamoto, H. Hamada, Catal. Today 10 (1991) 57 [3] M. Iwamoto, H. Yahiro, K. Tanda, N. Mizuno, Y. Mine, S. Kagawa, J. Phys. Chem. 95 (1991) 3727 [4] G.P. Ansell, A.F. Diwell, S.E. Golunski, J.W. Hayes, R.R. Rajaram, TJ. Truex, A.P. Walker, Appl. Catal. B 2 (1993) 81 [5] E.A. Lombardo, G.A. Sill, J.L. d’Itri, W.K. Hall, J. Catal. 173 (1998) 440 [6] R. Burch, J.P. Breen, F.C. Meunier, Appl. Catal. B 39 (2002) 283 [7] T. Miyadera, Appl. Catal. B 2 (1993) 199 [8] T. Miyadera, Appl. Catal. B 13 (1997) 157 [9] S. Satokawa, Chem. Lett. 3 (2000) 294 [10] M. Richter, R. Fricke, R. Eckelt, Catal. Letters 94 (2004) 115 [11] J. Shibata, K. Shimizu, Y. Takada, A. Shichi, H. Yoshida, S. Satokawa, A. Satsuma, T. Hattori, J. Catal. 227 (2004) 367 [12] J. Shibata, Y. Takada, A. Shichi, S. Satokawa, A. Satsuma, T. Hattori, Appl. Catal. B 54 (2004) 137 [13] S. Satokawa, J. Shibata, K. Shimizu, A. Satsuma, T. Hattori, T. Kojima, Chem. Eng. Sci. 62 (2007) 5335 [14] K. Shimizu, M. Hashimoto, J. Shibata, T. Hattori, A. Satsuma, Catal. Today 126 (2007) 266 [15] A. Aissat, S. Siffert, D. Courcot, R. Cousin, A. Aboukai's, C.R. Chimie 13 (2010) 515 [16] A. Aissat, D. Courcot, R. Cousin, S. Siffert, Catal. Today DOI: 10.1016/j.cattod.2011.01.033 (2011) 46 NOEA20I1 Zakopane 4-7 September 2011 K09 Influence of the crystallite size of nobel metals on the course of the DENOX reaction D. NAZIMEK¹, W. ĆWIKŁA-BUNDYRA¹ ¹ University of Maria Curie -Skłodowska, Faculty of Chemistry, Department of the Enviromental Protection, 20-031 Lublin, 3 M.Curie-Sktodowska Square, Poland Catalysis is one the most important fields in industry where small particles are applied. An extensive treatment of particle size effects in catalysis has recently published [1]. An effect of the metal crystallite size in the SCR process has been investigated for rhodium and platinum [2,3]. Kinetic analysis done by Oh [4] suggests that the rate-controlling step may shift from the low-temperature N₂/N₂O formation path to the high-temperature N₂ formation path with an increaese in the catalyst temperature. The present paper reports the effects of Pt, Rh, Pd and Ru dispersion on the course of the reaction between nitric oxide and carbon monoxide. Catalysts. The investigated catalysts M/AI₂O₃ was supported by y-AI₂O₃ obtained by classical impregnation method of the alumina supports by metal salts solution respectively and double impregnation of the alumina supports EDTA aqueous solution, following by metal salts solution respectively, [5], All obtained catalysts were reduced with hydrogen al 873K for 1 hour. The metals loadings were measured by X-ray fluorescence (XRE). Methods. Mean metal crystallite size was determined by X-ray diffraction (XRD) (occurance ± 30%) and from chemisorption measurements. Total surface areas of the catalysts examined were determined from argon adsorption at liquid nitrogen temperature by the BET method in a volumetric appartus ensuring a vacuum of al least 10'⁵ mm Hg. The same appartus was used for the determination of active surface areas of the reduced catalysts. The measurement of the activity and selectivity of the DENOX reaction was carried out in a gradientless reactor described in paper [6], All kinetic experiments were carried out in an atmosphere of helium and NO(1500 ppm) and C0(4500 ppm), determining the relationship between the reaction rate and temperature of this process. The reaction products were analyzed IR method and gas chromatography metod. The authors of papers [7-10], has been found a special role of B₅ sites existing on the metal surface area, in catalysis by metals in hydrogenolysis of alkane. The concentration of B₅ sites (calculated data) reaches a clear maximum in the different interval crystallite size of Pt, Rh, Pd and Ru. The increase in the Pt crystallites size induced an increase reaction rate of NO conversion and increase selectivity towards N₂O. In the case of rhodium catalysts, the reaction rate and selecticiy towards N₂O show a clear maximum as a function of the crystallites size of rhodium. However, that the only Rh, Pd and Ru catalysts was found correlation between number of B₅ sites for existing on the metal surface and selectivity reaction of DENOX towards N₂O. The observed maximum of the reaction rate conversion of NO and selectivity towards N₂O in the interval of Rh, Pd and Ru crystallite size is probably correlated with a concentration of low-coordination centers on the rhodium surface (probably B₅ sites). Probably B₅ sites may play a special role in the in the DENOX reaction by disociative chemisorption of NO on this site of active centers (including of B₅ sites). ¹ ² ³ ⁴ [1] M. Che, C.O. Bennett, Adv. Catal. 36 (1989) 55 [2] K. C. Taylor, Catal. Rev. - Sci. Eng. 35 (1993) 457 [3] K. C. Taylor, Sciences and Technology, vol. 5, Springer-Verlag, Berlin, 1984 [4] S. H. Oh, C. C. Eickel, J.Catal. 128(1991)526 47 NOEA20I1 Zakopane 4-7 September 2011 [5] J. Barcicki, D. Nazimek, W. Grzegorczyk, T. Borowiecki, R. Erąk, M. Pielach, React. Kinet.Calal. Lett. 17(1981) 169 [6] D. Nazimek, M. Kuśmierz, P. Kirszensztejn, P. J. Apllied Chem. 50 (2006) 41 [7] D. Nazimek, J. Ryczkowski, React. Kinel. Catal. Lett. 40 (1990) 145 [8] D. Nazimek, Appl.Catal. 12(1984) 227 [9] J. R. Anderson, Sci. Prog. Oxf. 69 (1989) 461 [10] D. Nazimek, J. Ryczkowski, Stud. Surf. Sci. and Catal. 119(1998)623 NOEA201I Zakopane 4-7 September 2011 KIO Structural-functional design of catalysts for gas emissions purification from nitrogen (I), (U) oxides S. ORLYK¹, S. SOLOVIEV¹, T. BOICHUK¹, P. KIRIENKO¹ ¹ LV.Pisarzhevsky Institute of Physical Chemistry of the NAS of Ukraine, 31 Prosp. Nauky, 03028 Kyiv, Ukraine, orlyk@inphyschem-nas.kiev.ua Issue of nitrogen oxides NₓOy (NOX and N₂O), one of the most dangerous pollutant the atmospheres, causing a hotbed effect, has reached 30 million ton in a year, and the most part from them has an anthropogenous origin. For last decade speed of allocation in atmosphere N₂O has considerably grown. For neutralization of diluted exhaust gases ( Nads + OHjds eq. 2 Temperalure-programmed reaction was performed in stoichiometric conditions in order to promote the NO reduction to N₂ in parallel to H₂ oxidation to H₂O (Figure 1). NO is activated on Rh/Al₂O₃ catalyst above 100°C and leads to the formation of nitrous oxide and nitrogen below 250°C. Above 250°C, the formation of ammonia and nitrogen predominates. On Rh/CeZrO2-Al₂O₃ (Figure 2), total conversion of NO is achieved above 180°C. Changes in selectivity occur. At low temperature (<150°C) N₂O and N₂ formation is observed, N₂ remains predominant. Above I5O°C, ammonia is produced, but in lower extent than in the case of Rh/Al₂O₃. The nitrogen yield reaches 100% at higher temperature. Clearly, the deposition of rhodium on ceria-zirconia improves catalytic properties on NO reduction with higher selectivity to nitrogen. 67 NOEA2011 Zakopane 4-7 September 2011 Figure I: Temperature-programmed reaction under 950ppm NO, 3000ppm H₂, 1025ppm O₂ after stabilization in IR cell on pre-reduced Rh/Al₂O₃ Figure 2: Temperature-programmed reaction under 950ppm NO, 3000ppm H₂, 1025ppm O₂ after stabilization in IR cell on calcined Rh/Ceo,₂Zr₀₃0₂-Al₂0₃ At the same time, surface adsorbed species are recorded and mainly consist on nitrosyl, nitrite and nitrate species. On Rh/Al₂O₃ at 20°C, three main bands of nitrosyIs were found: RhfNO)⁶* around 1896 cm’¹, Rh(NO)° at 1820 cm’¹ and RhfNO)⁶⁻ around 1714 cm¹. With the increase of the reaction temperature to 130°C, the disappearance of Rh(NO)° and Rh(NO)⁸" at the expanse of Rh(NO)^ is observed. At higher temperature (>200°C), no nitrosyls were present at the surface, in agreement with the total conversion of NO in this range. The formation of RhfNO)⁴* at 1905 cm’¹ is also detected between 25 and 100°C on freshly calcined Rh/CeZrO₂-Al₂O₃ catalyst in the presence of 950ppm NO, 3000ppm H₂,1025ppm O₂. The nature of nitrosyls absorbed species on Rh may influence the reactivity suggested by elementary steps from mechanism. The reactivity of nitrosyls species was also examined using transient experiments at low temperature. Relations between catalytic performances and spectroscopic measurements will be discussed in the presentation. [1] Y. Rename, F. Dhainaut, M. Frere, B. Ravanbakhsh, P. Granger, C. Dujardin, P.L. De Cola, Surf. Interface Anal. 42 530 (2010) 68 NOE A 2011 Zakopane 4-7 September 2011 C08 Controlling the surface dispersion of bao nano-domains on catalytic NOX storage materials via TiC>2 anchoring sites and improvement of sulfur poisoning tolerance E. ÓZENSOY¹*, G. SEDA VENTURE¹, E. VOVK¹ ¹ Department of Chemistry, Bilkent University, Ankara 06800, Turkey ^Corresponding author: ozensoy@fen.bilkent.edu.tr TiO₂ promoted novel NO, storage materials were synthesized in the form of BaO/TiO₂/Al₂O₃. The structure and the catalytic performance of these novel materials were investigated via TEM, SEM, EDX, Raman, BET, XRD, in-situ FTIR and TPD. Our results indicate that TiO₂ nano-domains can be effectively exploited to control the surface dispersion of BaO at the nanoscale and improve the sulfur poisoning tolerance of the NSR catalysts. Sulfur poisoning is a frequently observed catalytic deactivation phenomenon in heterogeneous catalysis. As a result, accumulation of SOX species in the form of sulfates, sulfites or sulfides on metal and/or metal oxide surfaces have been thoroughly studied in the literature in relevance to three-way catalysis (TWC), selective catalytic reduction (SCR), NOX storage reduction (NSR), hydrodesulfurization (HDS) and Claus process, in which various forms of A1₂O₃ are commonly utilized as the catalytic support material. Two major deactivation phenomena are often reported for the NSR catalysts where A1₂O₃ is used as a conventional support material. The first deactivation route involves thermal degradation of the structural integrity of the catalyst material due to solid state reactions between the catalytic components and sintering while the second one is associated with the sulfur poisoning. In our previous studies [1-3], we have investigated the effect of TiO₂ and FeOₓ on the surface distribution and the thermal stability of the NOX species formed during the nitration of the promoted support materials (TiOₓ/Al₂O₃ and FeO,/Al₂O₃) as well as promoted NOX storage materials (BaO/TiOₓ/Al₂O₃ and BaO/FeOₓ/AI₂O₃). In the current work [4], we focus our attention on the interaction of SOX with the TiO₂/Al₂O₃ and BaO/TiO₂/Al₂O₃ surfaces as well as the influence of TiO₂ domains on the NOX uptake after deactivation by SO₂ (g) + O₂ (g). Titania is used as a promoter to obtain novel catalytic support materials in the form of TiO₂/Al₂O₃ (Ti/AI) for NOX storage reduction (NSR) applications. Two different sol-gel preparation protocols (Pl, P2) were utilized in the synthesis, to obtain Ti/AI materials with different surface structures and morphologies at the nano-scale. Ti/Al(Pl) manifests itself as small (-10 nm) crystallites of TiO₂ (anatase) on y-AI₂O₃, while Ti/Al(P2)reveals an amorphous Al,TiyOz mixed oxide. The synthesized NOX storage materials were studied via XRD, Raman spectroscopy, BET surface area analysis, TPD, XPS, SEM, EDX-mapping and in-situ FTIR spectroscopy of adsorbed NO₂. NOX uptake properties of the BaO/TiO₂/y-Al₂O₃ materials were found to be strongly influenced by the morphology and the surface structure of the TiO₂/TiOₓ domains. The presence of Ti⁴⁺ surface sites provide additional NO, adsorption sites which can store NO, predominantly in the form of bridged/bidenlate nitrates. An improved Ba surface dispersion was observed for the BaO/TiO₂/y-AI₂O₃ materials synthesized via the co-precipitation of alkoxide precursors which was found to originate mostly from the increased fraction of accessible TiO₂/TiOₓ sites on the surface. These TiO₂/TiOₓ sites function as strong anchoring sites for surface BaO domains and can be tailored to enhance surface dispersion of BaO. TPD experiments suggested the presence of at least two different types of NO, species adsorbed on the TiO₂/TiO, sites, with distinctively different thermal stabilities. The relative stability of the NO, species adsorbed on the BaO/TiO₂/y-AI₂O₃ system was found to increase in the following order: NO7N₂O₃ on alumina « nitrates on alumina < surface nitrates on BaO < bridged/bidentate nitrates on large/isolated TiO₂ clusters < bulk nitrates on BaO on alumina surface and bridged/bidentate nitrates on small TiO₂ crystallites homogenously distributed on the surface < bulk nitrates on the BaO sites located on the TiO₂ domains. 69 NOEA2011 Zakopane 4-7 September 2011 The functionality/performance of these materials upon SO, and subsequent NO, adsorption were investigated with temperature programmed desorption (TPD) and in-situ Fourier transform infrared (FTTR) spectroscopy. Figure 1. (a-d) FTIR spectra obtained after the saturation of fresh (black curves) and sulphur-poisoned (red curves) y-Al₂O₃, TiO₂ (anatase), Fi/Al (Pl) and Ti/Al (P2) surfaces with NO₂ at room temperature, respectively. SO, adsorbs much stronger on pure y-Al₂O₃ with respect to pure TiQ: (anatase). Nitration of the Ti/Al (P1,P2) support materials poisoned with SO, led to a decrease in the total NO, uptake and lowered the NO, adsorption strength. Overall stabilities of the adsorbed SO, species tend to increase in the following order: TiO₂ (anatase)« y-Al₂O₃ < Ti/Al (Pl) = Ti/Al (P2). Our results reveal that promotion of the conventional y-AI₂O₃ support material with TiO₂ in the form of Ti/Al (P1,P2) leads to a larger SO, uptake. Thus, unlike the acidic TiO₂ (anatase) surface, which has a relatively limited SO, uptake with respect to y-Al₂O₃, synthesized Ti/Al (P1.P2) mixed oxides reveal new additional SO, storage sites. These sites may function as sacrificial SO, binding sites in NSR catalysts by preventing the sulfur poisoning of the alkali or alkaline earth oxide sites used as NO, storage units. [1] E. Kayhan, S. M. Andonova, G. S. Senturk, C. C. Chusuei, E. Ozensoy, J. Phys. Chem. C 114 (2010)357 70 NOEA20I1 Zakopane 4-7 September 2011 C09 NOx reduction and methane oxidation over mesoporous silica supported palladium J. BASSIL¹, A. A1BARAZI², P. Da COSTA², M. BOUTROS¹ ¹ Universite Libanaise, Faculte des sciences II, Laboratoire de Chimie Physique des Materiaux (LCPM), Campus Fanar, BP 90656, Jdeideh - Liban, e-mail: boutrosmaya@hotmail.com ² Universite Pierre et Marie Curie, UPMC Paris 6, Institut Jean Le rond d'Alembert (UMR 7910), 2 place de la gare de ceinture, 78210 Saint Cyr I’ecole, France, patrick.da_costa@upmc.fr Silica or aluminosilica with an hexagonal structured mesopore network like MCM-41 and SBA-15 are characterized by high specific surface area, porous volume and adjustable pore size diameter make them ideal support of catalysts. Such mesoporous silica SBA-15, modified with copper, iron, Mn, were already studied in SCR of NO by ammonia [ 1 ]. This technology is not so easy to implement on automotive field due to difficulties in the storing or handling of NH₃. The abundance of methane makes the SCR of NO, by methane a promising and attractive technology for the abatement of NO, emissions from stationary sources [2]. In this work, some materials Pd-SBA-15 were synthesized and characterized by various techniques.We investigate the influence of the impregnation method on the physico-chemical properties of SBA-15 support, the morphology of palladium nanoparticles and the catalytic performances of mesoporous supported palladium catalysts in methane oxidation and NO, reduction by CH₄. The mesoporous silica SBA-15 was synthesized using a hydrothermal method described by Zhao et al [3], The palladium precursor used is tetramine palladium(II) nitrate Pd(NH₃)₄(NO₃)2. The catalysts Pd-SBA-15 were prepared by ion exchange method (Pd-SBA-15(IE)) or incipient wetness impregnation (Pd-SBA-15(IWI)). Then, the samples were calcined under air flow at 500°C for 2 h. The catalysts were characterized by various techniques and tested for the reduction of NO, by methane in the presence of oxygen (500 ppm NO + 1500 ppm CH₄ + 7% O₂ in Ar; GHSV = 22100 h¹). The structure and the mesoporosity of the different solids were determined by their low-angle XRD patterns and N₂ sorption isotherms, respectively. Compared to the pure calcined silica SBA-15, Figure 1 shows that Pd-SBA-15 (IWI) has three well-resolved characteristic diffraction peaks which are attributed to 100, 110 and 200 of hexagonal structure. In the case of Pd-SBA-15 (IE), (Fig. I curve c), a gradual decrease of the intensities of each peak is observed, related to the strongly alcaline medium used during the method of impregnation. Il was noticed that the diffraction peaks of palladium containing mesoporous silica, are less shifted to higher values than those of pure SBA-15 silica related to a decrease of structural parameters (dₕₖₗ and ao). This difference is maybe related to the presence of Pd particles inside the mesopores channels of SBA-15 support. N₂ adsorption-desorption isotherms of calcined SBA-15 support and Pd-SBA-15 samples exhibit characteristic type IV isotherms with a Hl hysteresis loop as defined by IUPAC (Figures not shown). The textural parameters of the Pd-SBA-15 samples prepared with two different methods of impregnation are listed in Table 1. The inclusion of palladium by ion exchange into the structure of SBA-15 conducted to a large modification of the specific surface area (- 35%) that is not the case of Pd-SBA-15 (IWI) sample (- 17%). 71 NOE A 2011 Zakopane 4-7 September 2011 Table I: Physico-chemical properties of SB A-15 and Pd-SBA-15 samples Samples v Si Pd ^BET * pores Spores (wt%) (wt%) (m2 g1) (cm’g1) (nm) Si-SBA-15 - - 800 1.15 6.7 Pd-SBA-15 (IWI) 48 0.18 665 0.85 5.5 Pd-SBA-15 (IE) 48 0.25 525 0.75 5.2 TEM images of Pd-SBA-15 samples indicate that these solids are well mesostrutured despite the introduction of metal on the support. Dispersed palladium nanoparticles are mainly located inside the pore channels in the case of Pd-SBA-15 (IE). However, the detection of palladium particles is more difficult for Pd-SBA-15 (IWI) sample. Small PdO nanoparticles and Pd(II)O clusters species were detected by UV-vis and XRD high angles. Figure I. X-ray diffraction patterns of (a) SBA-15, (b) Pd-SBA-15 (IWI) and (c) Pd-SBA-15 (IE) 72 NOEA 2011 Zakopane 4-7 September 2011 Temperature (°C) Figure 2. Steady-state methane conversion as junction of temperature for SBA-15 and Pd-SBA-15 samples The palladium catalysts prepared on the mesoporous silica have a lower activity for the reduction of NOX by CH₄ ( < 10%). The methane oxidation started at about 300°C; then the conversion into CO and CO2 increased drastically with the reaction temperature and the complete conversion was reached al 400°C and 500°C for Pd-SBA-15 (IE) and Pd-SBA-15 (IWI) respectively (Fig. 2). To conclude, new catalysts were synthesized by depositing Pd on SBA-15. Whatever the method of impregnation, the particles of palladium are very small and well dispersed on the surface of support. The Pd/mesoporous materials demonstrate the better oxidation of methane into CO and CO₂. [ I ] X. Liang,, J. Li,, Q. Lin, K. Sun, Catal. Commun. 8 (2007) 1901 [2] R. Marques, L. Mazri, S. Da Costa, F. Delacroix, G. Djega-Mariadassou, P. Da Costa, Catal. Today 137 (2008) 179 [3] D. Zhao, Q. Huo, J. Feng, F. Chmelka, G.D. Stucky, J. Am. Chem.Soc. 120 (1998) 6024 73 NOEA 2011 Zakopane 4-7 September 2011 K12 Design of the Catalysts for the Removal of Diesel Soot and NOX Z. ZHAO¹ ¹ State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China, e-mail: zhenzhao@cup.edu.cn Particulate materials (PM, mainly containing diesel soot) and NOx are very serious and most difficult to be removed pollutants emitted from diesel enginefl-5]. The combination of traps and oxidation catalysts appears to be one of the most efficient after-treatment techniques for the removal of diesel PM, and research and development of highly active catalysts for diesel soot combustion become an urgent task. Moreover, the simultaneously catalytic removal of diesel soot particle and NOx is also a very significant method because it can purify the two kinds of serious pollutants from diesel engine exhausts at same time [1,2], In this lecture I will mainly discuss the catalysis nature and the design of the catalysts for the combustion of diesel soot. On the one hand, the good redox property and the strong ability to activate oxygen of catalysts play significant roles in obtaining high catalytic activity for soot oxidation. Thus, the intrinsic factors including the compositions, structures, the oxidation states, the oxygen vacancy, and the size of catalysts particles are important for the catalysts to getting the high catalytic activity for soot oxidation. On the other hand, since the soot oxidation over a catalyst is a complicated gas-solid (soot)-solid (catalyst) multiphase reaction, besides the intrinsic factors, the external factors, especially the contact efficiency between catalyst and soot, also plays a significantly important role in the oxidation of soot particles. Based on the literature [1-8] and our group’s recent works [9-19], four ways to promote the contact efficiency between diesel soot particle and catalyst were proposed / summarized. Firstly, the mobility of the ions in the catalysts under the melting conditions is much higher than that under normal solid conditions. The high mobility of the ions in the catalysts is favorable for getting the good contact between catalysts and diesel soot. Therefore, the compounds with low melting points or the two kinds of mixed oxides with low eutectic melting point should be good candidate catalysts for soot oxidation[3,9]. Secondly, nanometric catalysts have high specific surface area and good mobility, which facilitates the contact between diesel soot and catalyst, and decreases the activation energy for diesel soot combustion reaction. Thus it results in the increase of catalytic activities [10-13], Thirdly, the pore diameter of macroporous catalysts is big enough to permit soot particulate to enter their inner pores. And the open pore structure can facilitate the diffusion of soot into the inner pore channel, which offers the advantage of highly accessible surfaces [8,14-18]. Therefore, the contact efficiency is dramatically enhanced. Fourthly, the contact mode among catalyst, diesel soot and reactant gas become into solid-gas-solid contact from solid-solid-gas with the incorporation of strong oxidant, such as NO₂ molecule. Therefore, the contact between soot and catalyst can be improved dramatically [3,6,11,19], The most important character for the highly active catalysts for the combustion of diesel soot is the strong ability to activate oxygen al low reaction temperatures, especially for getting the very low ignition temperature for soot oxidation, which is the most important characteristics that the excellent soot oxidation catalysts should possesses. In this talk, several systems of the catalysts including the oxides with low melting points, the nanosized multi-component bulk Co-based, or Mn-based perovskite-type complex oxides, nanometric CeO₂-supported cobalt oxides, nano-macroporous Ce-Zr solid solution oxides, nano-macroporous Fe-based, Co-based, or Mn-based perovskite-type complex oxides, and nano-macroporous perovskite LaFeO₃-or nano-macroporous Ce-Zr solid solution oxide-supported gold catalysts were summarized and their catalytic performances for diesel soot oxidation were also investigated and compared. The catalysts were characterized by the techniques of N₂-adsorption and desorption, SEM.TEM, TG-DTA, XRD, IR, UV-Vis, H₂-TPR, O₂-TPD and NO-TPD. Moreover, the reaction mechanism of diesel soot oxidation 75 NOEA2011 Zakopane 4-7 September 2011 on the multi-component oxide catalysts was studied by the means of in-situ UV-Raman and MS-TPSR [19]. This work was supported by the National Natural Science Foundation of China (No. 20833011, 20803093 and 21073235), the 863 program of China (No. 2009AA06Z313). [ 1 ] K. Yoshida, S. Makino, S. Sumiya, G. Muramatsu, et al., SAE Paper 892046 (1989) [2] Y. Teraoka, K. Nakano, S. Kagawa, W.F. Shangguan, Appl. Catal. B 5 (1995) L18 [3] J.P.A. Neeft, W. Schipper, G. Mui, et al., Appl. Catal. B 11 (1997) 365 [4] N.Russo, S. Furfori, D. Fino, et al., Appl. Catal. B 83 (2008) 85 [5] M.Adamowska.A. Krzton, M. Najbar, et al., Appl. Catal. B 90 (2009) 535 [6] J. O. Uchisawa, A. Obuchi, Z. Zhao and S. Kushiyama, Appl. Catal. B 18 (1998) LI83 [7] A.L. Kustov, M. Makkee, Appl. Catal. B 88 (2009) 263 [8] M. Sadakane, T. Asanuma, J. Kubo, et al., Chem. Mater. 17 (2005) 3546 [9] J. Liu, Z. Zhao, C. Xu ,el al., Applied Catal. B 61 (2005) 36 [10] H. Wang , Z. Zhao, C. Xu, et al., Catal. Letters 102 (2005) 251; 124 (2008) 91 [11] J. Liu, Z. Zhao, C. Xu, et al., Applied Catal. B 78 (2008) 61 [12] J. Liu, Z. Zhao, C. Xu, et al., Applied Catal. B 84 (2008) 185 [13] J. Liu, Z. Zhao, C. Xu, et al., J. Phys Chem. C 113(2009) 17114 [14] G. Zhen, Z. Zhao, et al., Chem. Commun. 46 (2010) 457 [ 15] J. Xu, J. Liu, Z. Zhao, et al., I., J. Catal., DOI: 10.1016/j.jcat.2011.03.024 (2011) [16] J. Xu, J. Liu, Z. Zhao, et al., Catal. Today 153 (2010) 136 [ 17] Y. Wei, J. Liu, Z. Zhao, et al.,, Angew. Chem. Int. Ed 50 (2011) 2326 [18] Y. Wei, J. Liu, Z. Zhao, et al., Energy & Environ. Sci, DOI:l0.1039/C0EE008l3 (2011) [ 19] J. Liu, Z. Zhao, C. Xu, et al., Catal. Letters 120 (2008) 148; J. Phys Chem. C 112 (2008) 5930 76 NOEA 2011 Zakopane 4-7 September 2011 CIO Catalytic filters for the simultaneous removal of soot and NOX: influence of the alumina precursor on monolith washcoating and catalytic activity M. E. GALVEZ¹, S. ASCASO¹,1. TOBIAS¹, R. MOLINER¹, M. J. LAZARO¹ ^Tnstituto de Carboquimica, CS1C, Miguel Luesma Castan, 4. 50018 Zaragoza (Spain), e-mail: mlazaro@icb.csic.es Due to their optimal fuel economy and excellent durability, the demand for light-duty diesel vehicles has increased notably in the last years, this trend expected to continue in the near term future [1,2]. The design of the combustion process in diesel engines does, however, result in high emission of particulate matter, i.c. soot. Engine modifications have helped to lower the emission of particulates in diesel engines, conforming the previously existing legislative demand. Still, there is a trade-off between the reduction of particulate matter emission and nitrogen oxides (NOX) control. Thus, the use of after-treatment technologies is required, and each time more efficient technologies are being hunted in order to meet the upcoming emission standards [3]. Under typical lean-bum operation conditions of diesel engines, three-way catalysts are not efficient in reducing NOX [4,5]. One of the latest research efforts focuses on the simultaneous elimination of both contaminants, by means of catalytic filtration of the exhaust gas. Bi-metallic alumina-supported catalysts consisting of Cu, Co and V oxides, together with alkali promoters, namely K, have shown outstanding activity in both soot oxidation and NOX reduction at temperatures from 250-650°C [6], even when the catalytic material was supported onto structured materials, such as cordierite honeycomb monoliths [7]. However, textural properties of the catalytic layer, which are strictly dependant on the type of alumina precursor employed, might influence the extent and uniformity of monolith coating, reactant diffusion towards the catalytically active sites as well as soot-catalyst contact, determining the activity of the catalytic filter in the simultaneous removal of soot and NOX. Cordierite monoliths (2MgO-2AI₂O₃-5SiO₂, Coming, 400 cpsi) were selected as filtering material. Several AI₂O₃ gels were synthesised by sol-gel synthesis. Disperal, Disperal 20, Disperal 40 and Disperal 60 (Sasol GmbH), differing in powder surface area, particle and dispersed particle size, were used as the alumina precursors. Concentrated nitric acid was added as peptizing agent. Metals and K were incorporated to the mixture by means of Cu(NO₃)₂-3H₂O, Co(NO₃)₂-6H₂O and NH₄VO₃ and KNO₃. Cylindrical shaped monoliths (1x2.5 cm) were subjected to oxidation in concentrated HNO₃ for approximately 5 minutes. Coating was performed by forced circulation of the gels through the channels of the cordierite monoliths, using a peristaltic pump. After 30 minutes, the coated monoliths were dried in a rotating oven at a temperature of 65°C for 24 h, and further subjected to calcination at 450°C during 4 h. Physical and chemical characterization was carried out by N₂ adsorption, XRD, SEM-EDX and temperature programmed reduction (TPR). A carbon black, CB (Cabot, Elftex 430) was used as model compound of soot. The coated monolith was introduced into a dispersion of 0.2 g of CB in 180 mL of n-penlane, stirred for I min and dried at 65°C for 1 hour. The catalytic activity of the filters in the simultaneous removal of CB and NOX was tested in a fixed-bed bench-scale apparatus. A reactant gas containing 600 ppm NO-5% O₂ in Ar was flowed at 50 mL/min through the catalytic filter, corresponding to a gas residence time of approximately 2.5 seconds. Dynamic experiments were performed at temperatures between 250 and 650°C, using a healing rate of 5 K/min. Concentrations in the exiting gas were analyzed in a mass spectrometer (Balzers 422) and by gas chromatography (HP 5890). The catalytic fillers prepared substantially differed in textural and morphological features, depending on the type of precursor employed in their preparation. Properties of the different alumina gels prepared were as well strongly influenced by the alumina precursor, i.e. suspensions containing Disperal 60 (D60) gelified poorly due to much higher dispersed particle size (350 nm) in comparison with other alumina precursors (D: 80 nm, D20: 150 nm, D40: 300 nm). Viscosity increases in the order D>D20>D40>D60. 77 NOEA 2011 Zakopane 4-7 September 2011 As a result, cordierite monoliths coated using D60 were non-uniformly covered by a thinner catalytic layer; uncoated monolith channels were observed by means of SEM-EDX whereas at some points agglomeration of material was observed. On the other had, coating using the gels prepared using 1)60 and 1)40 led to catalytic layers presenting less number of cracks in comparison to I) or 1)20, as can be observed in Eig. I. Layer adherence thus notably improved by means of using 1)60, 1)40 or even 1)20 with respect to I). Textural properties determined from N₂ adsorption isotherms evidence higher surface areas for the catalytic filters prepared using D, as shown in Table 1 for the particular case of a the catalytic filter 6/0.04/5:10/Co. Pore size increases in the order D60>D40>l)20>I), whereas VBJH, corresponding to mesopores, decreases following the opposite trend. While less number of cracks are formed, D40 and 1)60 resulting in non-uniform coverage of the monolith surface leave totally or partially uncovered a greater part of the original macroporous structure of the cordierite material. Table I. Surface area, total and mesopore volume, and average pore diameter, for 6/0.04/5:10/Co, prepared using the different alumina precursors. D60 D40 1)20 1) .S'B,.;7- (m2/g) 2.3 3.1 5.6 12.4 V„ (cm3/g) 0.021 0.027 0.026 0.026 VHJH (em’/g) 0.021 0.028 0.027 0.027 AI>Cu>Zr>Ce>Cr. The Fe₂O₃/CuO catalyst has higher activity for N₂O decomposition than the Fe₂O₃/AI₂O₃ system at the temperature of 800°C. Moreover, at 900°C higher activity was observed for the La-modified catalyst. [1] R. T. Ellington, M. Meo, Chem. Eng. Prog. 7 (1990) 58 [2] J. Perez-Ramirez, F. Kapteijn, K. Schoffel, J. A. Moulijn, Appl. Catal. B 44 (2003) 117 [3] A. Gołębiowski, J. Kruk, M. Wilk, Investigation of N₂O Catalytic Decomposition at High Temperature, International Symposium on Air Pollution Abatement Catalysis 2005, Cracow, Poland [4] G. Giecko, T. Borowiecki, W. Gac, J. Kruk, Catal. Today 137 (2008) 403 [5] J. Zieliński, React. Kinel. Catal. Lett. 17 (1981) 69 93 NOEA2011 Zakopane 4-7 September 2011 C16 Stoichiometric and non-stoichiometric Perovskite-based catalysts for the catalytic decomposition of N2O from nitric acid plants Y. WU¹, X. NI\ P. GRANGER¹, C, DUJARDIN¹ ¹ University Lille Nord de France, Unite de Catalyse et de Chimie du solide, CNRS UMR 8181, City Scientifique, Batiment C3, 59655, Villeneuve d’Ascq, France, e-mail: christophe.dujardin@univ-lillel.fr There is a growing interest to minimize the emissions of nitrous oxide (N₂O) as side-product from nitric acid plants due to a global wanning potential of approximately 300 times higher than that of CO₂ [1]. Different strategies have already been implemented at industrial scale but they are still suffering from significant drawbacks essentially associated to a poor selectivity and sometimes a short lifetime in particular when the catalytic process is inserted downstream the ammonia burner. Previous in-situ XRD measurements performed in our laboratory revealed the excellent thermal stability of perovskite based catalysts in the presence of water vapor at high temperature [2], which suggests its potential application for the decomposition of nitrous oxides from nitric acid plants. The non-stoichiometric perovskite-based catalysts were examined in order to investigate a possible support effect of segregated oxides on perovskite that could enhance or lower die catalytic activity subsequently. An additional aspect has to be taken into account associated with the catalyst selectivity because the decomposition of NO must be avoided to preserve the cost efficiency of those typical industrial plants. Two series of stoichiometric and non-stoichiometric Perovskite-based catalysts (LaCO|.yO₃±₎L and I^i-xCoojFeojO^ were synthesized according to a conventional sol-gel method involving a citrate route [3]. Precursors thus obtained were dried overnight at 80 °C then calcined in air at 600°C or 900 °C for 8 h. The prepared catalysts were characterized by BET, XRD, Raman, H₂-TPR and XPS. Temperatureprogrammed experiments were performed in a fixed-bed flow reactor using 0.7 g of catalyst with a total flow of 15 L.h ’ within a temperature range between 20 and 900 °C. The reactant mixture was typically composed of 0.1 vol.% N₂O, 5 vol.% NO, 6 vol. % O₂, 15 vol. % H₂O and balanced by He. A second catalytic test was performed after ageing overnight at 900°C under reactant mixture in order to characterize the stability of our catalysts. 95 NOEA2011 Zakopane 4-7 September 2011 The XRD patterns recorded on the catalysts evidence the rhombohedral structure of LaCoO₃ and a slight segregation of La₂O₃ on LaCo₁.yO₃±x samples that could be related with the increase of specific surface area up to 12 m¹ ² ³/g (LaCoo.₈0₃ calcined at 900°C). For Lai.JCo₀₈Fe₀₂O₃±>. samples, a progressive segregation of cobalt oxide is revealed with decreasing lanthanum stoichiometry but the specific surface area remains almost unaffected. The reducibility of these series of catalysts is examined by using H₂-temperature-programmed reduction. The typical profile related to H₂ consumption exhibits 2 domains of reduction, the reduction of Co³⁺ into Co²⁺ around 300-450°C and the subsequent reduction of Co²⁺ into Co⁰ above 500°C in agreement with H₂ consumption [3]. The modification of stoichiometry slightly changes the reducibility accompanied with a shift of temperature T^ for both domains. The characterisation of solids clearly evidences the formation of perovskite structure and the segregation of either La₂O₃ that enhances the specific surface area for LaCoₗ yO₃±ₓ or the preferential segregation of Co^ in the case of La₁.ICo₀ ₈Fe₀ ₂O₃±x solids. We pay a special attention to a possible support effect that could involve the stabilisation of active phase. The Figure 2 compares the catalytic activity for the N₂O decomposition into N₂ for the freshly calcined catalyst and the catalyst aged under reaction conditions at 900°C overnight. For all the samples, they show an exclusive selectivity towards N₂O decomposition without NO loss. A strong activity enhancement in N₂O conversion is observed on the substituted sample (LaCoo₈Feo,₂0₃) and the introduction of iron on LaCoO₃ leads to a stabilisation of the solid revealed by a decrease of the deactivation after ageing. This synergy effect is correlated to the improvement of oxygen mobility which agrees with the observation of H₂-TPR. Moreover after ageing procedure, the catalytic activity of Lao.ęCoo ₈Feo.₂0₃±₃. sample remains higher than stoichiometric one. The influence of the support and on the nature of segregated oxide will be discussed during the presentation. Figure 2: Comparison of N₂0 conversion curves of Lai.ₓCoQgFeo₂03^ of fresh sample and after ageing overnight under 0.1 %N₂0+5%N0+6%0₂+15%H₂O +He [1] J. Pćrez-Ramirez, E Kapteijn, K. Schoffel, J.A. Moulijn, Appl. Catal. B 44 (2003) 117 [2] S. Muller, J.P. Dacquin, Y. Wu, C. Dujardin, P. Granger, P. Burg, Catalysis Today, DOI: CATTOD-D-10-00453R1 [3] I. Twagirashema, M. Engelmann-Pirez, M. Frere, L. Burylo, L. Gengembre, C. Dujardin, P Granger, Catal. Today 119 (2007) 100 96 NOEA201I Zakopane 4-7 September 2011 KI4 N2O catalytic decomposition - from laboratory experiment to industry reactor L. OBALOVA¹,², K. JIRATOVA³,F. KOVANDA⁴ VŚB - Technical University of Ostrava, ¹ Faculty of Metallurgy and Materials Engineering ¹ Centre for Environmental Technologies, 17. listopadu 15, 708 33 Ostrava, Czech Republic ³ Institute of Chemical Process Fundamentals CAS v.v.i., Rozvojova 135, 165 02 Prague, Czech Republic ⁴ Institute of Chemical Technology, Department of Solid State Chemistry, Technicka 5, 160 00 Prague, Czech Republic In last years, the catalytic decomposition of N₂O as a method for abatement of N₂O emissions in waste gases attracts increasing attention due to the expected inclusion of N₂O in the greenhouse gas trade. Many research groups are focused on the development of suitable catalysts for this reaction because it is still a problem to find the catalyst with sufficient activity and stability in real off-gas conditions due to water, oxygen and NOX inhibition effects. Multicomponent mixed oxides prepared by thermal treatment of layered double hydroxide (LDH) precursors seem to be promising catalysis for this reaction. Layered double hydroxides with general chemical composition of |Mll|.ₓMl"ₓ(OH)₂|x⁺[Aⁿₓ/ₙ ,yH₂O]x where M¹¹ and M¹¹¹ are divalent and trivalent metal cations and A"' is an n-valent anion (often carbonate) consist of positively charged hydroxide layers separated by interlayers containing anions and water molecules. Thermal treatment of LDH precursors gives finely dispersed mixed oxides of M¹¹ and M¹¹¹ with large surface area and good thermal stability. Intrinsic kinetic data were obtained in laboratory experiments of N₂O decomposition over grained LDH-related mixed oxides; these data were used for modeling of catalytic performance of catalyst particles suitable for industrial use and compared with experiment. Pseudo-homogeneous one-dimensional model of an ideal plug flow reactor in isothermal regime was applied; the effect of internal and external mass transport was described by effectiveness factor. The N₂O abatement by using a catalytic reactor situated downstream the DcNOₓ technology in nitric acid production unit was estimated, based on laboratory data of N₂O decomposition in simulated off gas from nitric acid production. This work was supported by the Technology Agency of the Czech Republic (project No. TA 0/020336) and EU project No. CZ. 1.05/2.1.00/03.0100 „Institute of Environmental Technologies". 97 NOEA2011 Zakopane 4-7 September 2011 CI7 The application of metallic iron for N2O reduction at higher temperature and oxygen presence J. LASEK¹*, B. GRADOŃ² ¹ Institute for Chemical Processing of Coal, Zamkowa 1, 41-803 Zabrze, Poland ² Department of Metallurgy, Silesian University of Technology, Krasińskiego 8, 40-019 Katowice, Poland Corresponding author (J. Lasek) jlasek@ichpw.zabrze.pl The nitrous oxide is recognized as a pollutant of known, negative impact on environment. Il is a greenhouse gas. Due to a long lifetime in the atmospheric conditions, its molecules can migrate to the stratosphere and there lake a part in the stratospheric ozone depletion. The N₂O can be formed in many natural processes but substantial share to its global emission is contributed by human activities, mainly acid production, agriculture and combustion processes for production heat and electricity. The level of the N₂O emission from the combustion equipments depends mainly on type of fuel and temperature. Concentrations of the N₂O in the flue gases leaving industrial gaseous furnaces and pulverized coal boilers, operating al high temperatures, are very small and do not exceed 5 ppm. Nevertheless, much higher values are observed in case of the fluidized bed combustors (FBC): 20-200 ppm depending on temperature and combustion air excess. The highest emissions are observed from circulating fluidized bed boilers. On the other hand this combustion technology becomes more and more popular due to ability to utilize low-rank coals, biomass and waste with high combustion efficiency and environmentally favorable performance. The paper presents the results of the experimental investigation of nitrous oxide reduction by reaction with metallic iron, within the temperature range of 600-850°C. Experiments were carried out in a one-dimensional tubular flow reactor externally heated in an electrical furnace. The spherical and cylindrical iron samples of well-defined and fixed surface area were placed in the center of the reactor. Mixtures of N₂O/N₂, N₂O/O₂/N₂ and NO/CO₂/N₂ of different molar compounds fractions were continuously fed into the reactor. On basis of these experiments the intrinsic rate of the reaction between nitrous oxide and Fe in the first stage of iron oxidization was measured. The obtained results are compared with the literature data. An impact of oxygen present in reaction zone on inhibition of deN₂O process has been investigated. A very strong and fast decreasing of N₂O reduction was observed when more than 2 vol% O₂-containing gas mixture was introduced into reaction zone. The surfaces and cross-sections of partly oxidized iron samples were observed using a scanning and light microscopes. 99 NOEA 2011 Zakopane 4-7 September 2011 C18 Copper ionic pairs as active sites in N2O decomposition on CuOₓ/CeO2 catalysts A. ADAMSKI¹, W. ZAJĄC¹³, F. ZASADA¹, Z. SOJKA¹ ¹ Faculty of Chemistry, Jagiellonian University,3 Ingardena St., PL 30-060 Cracow ¹ AGH University of Science and Technology, Faculty of Energy and Fuels, Al. Mickiewicza 30, PL 30-059 Cracow Ceria-supported copper systems belong to the important class of heterogeneous catalysts extensively studied for both fundamental and applied reasons. Structural similarity of copper centers to those occurring in selected enzymes, particular distribution of copper species between surface and bulk, oxidative power of ceria and specific interaction of surface centers with small reactant molecules from the gas phase are responsible for still growing interest in studying such materials. One of the most important catalytic applications of ceria-supported systems can be redox processes including CO or CH₄ oxidation to CO₂, soot oxidation in the presence of NOX, etc. Taking into account that nitrous oxide reductase is a dimeric copper - dependent bacterial enzyme that catalyses the reduction of N₂O to N₂ and that copper dimers can be formed within CuOₓ/CeO₂ systems quite easily, it could be assumed that coupled copper species constitute active sites for deN₂O reaction also in the case of ceria-supported catalysts. In the current structural (XRD, SEM) spectroscopic (EPR, RS) and catalytic studies, supported by DFT calculations, the role of mono- and dimeric copper centers in deN₂O reaction was elucidated. Particular attention was paid to the structure and localization of Cu²⁺-Cu²⁺ pairs in CeO₂ matrix, conditions of their formation and stability. Ceria was synthesized from O.IM aqueous solution of Ce(NO₃)₃ by stepwise precipitation with ammonia. Final support was calcined in air at 600°C for 6h. Copper-functionalized ceria samples, containing 5 mol. % of CuO, were synthesized in two ways: by coprecipitation with concentrated solution of ammonia or by impregnation of the CeO₂ support with an aqueous solution of Cu(NO₃)₂. Catalysts were calcined at 600°C/6h. Catalytic tests in deN₂O reaction were performed in TPSR mode with QMS detection. Quartz reactor filled with ca. 300 mg of sample was heated with the rate of 10°C/min in the temperature rangeof 20-700°C. The reactants (5 % N₂O/He, 3% O₂/He) flow rate of 7000 h'¹ was used. For all calculations the unrestricted DFT was chosen with use of the DMol³ program package as implemented in Materials Studio of Accelrys Inc. To describe exchange-correlation effects the functional of generalized gradient approximation (GGA) level was chosen with parametrization proposed by Perdrew et al. (PW9I). All slab calculations were performed using standart Monckhorst-Pack grid (2x2x1 sampling mesh) with Fermi smearing with o parameter set to 0.01 Ha and a cutoff energy of 4.5 A. 101 NOEA2011 Zakopane 4-7 September 2011 Figure 1. Model geometry ofCu-doped CeO₂ surface. Calculated surface energies indicate that the most stable termination of CeO₂ Crystalites is (111) and thus Crystalite shape predicted via Wulff construction is closed only by (111) surface which is in agreement with experimental data. Cu dopping was modeled by exchanging two neighboring Ce atoms with Cu ions and creating 0,1 or 2 oxygen vacancies (Fig.l) Figure 2. Catalytic activity of CuO/CeO₂ samples (5 mol. %) in A) dry B) wet conditions. Samples prepared by: a - impregation, b - coprecipitation followed by impregnation, c - coprecipitation. 102 NOEA201I Zakopane 4-7 September 2011 Catalytic tests showed that the CuOₓ/CeO₂ samples obtained by impregnation were distinctly more active (exhibited lower Tₓ temperatures) in N₂O decomposition in comparison to those synthesized by coprecipitation. This effect was practically insensitive to the presence of water (Fig. 2). Corresponding Tso values were equal to 430 and 540 °C in dry atmosphere and was shifted up to 500 and 600 °C in the atmosphere containing 3 vol. % of H₂O. On the other hand, basing on the analysis of EPR, suggesting predominance of isolated copper species in the case of impregnated samples, it can be inferred that monomeric copper species are much more efficient as the active sites in N₂O decomposition in comparison to dimeric copper centers. Observed effect can be even more surprising if we take into account, that the determined from EPR spectra average Cu²⁺-Cu²⁺ distance in ionic dimers, equal to ca. 2.42 A, fits relatively well to the N-0 distance (ca. 2.55 A) in the bent N₂O molecule (reactive mode). Adsorption of N₂O on copper dimers should thus be preferrencial in comparison to that, when monomeric centers are engaged. Also DFT results suggested the lowest TS barrier (25.9 kcal/mol) for N₂O adsorption on two vicinal copper centers exposed on CeO₂ (111) surface. Structural and morphological considerations led us to the conclusion that the confirmed relationships between structure of differently synthesized CuOₓ/CeO₂ samples and their activity in deN₂O reaction does not support the initial hypothesis ascribing a principal role in N₂O decomposition to the coupled copper ions. Due to rather strong discrepancies in the structure and lattice parameters of CeO₂ and CuO, as well as due to differences in sizes, electronegativities and charges of Ce⁴⁺ and Cu²⁺ ions, formation of a substitutional solid solution, in which vicinal copper centers could interact magnetically, giving rise to the characteristic fine structure in the EPR spectra, seems to be quite impossible. Most probably these entities are located in the subsurface interparticle layers, where copper ions segregate during thermal treatment of the CuOₓ/CeO₂ samples. Such ions remain thus inaccessible for the reactants from the gas phase and even present, they cannot play a role of adsorption sites for N₂O molecules. The research was partially supported in the framework of the national grant No. NN 507 426 939 and carried out with the equipment purchased thanks to the financial support of the European Regional Development Fund in the framework of the Polish Innovation Economy Operational Program (contract no. POIG.02.0I.00-I2-023/08). 103 POSTER SESSION NOEA20II Zakopane 4-7 September 2011 PS01 Dual role of surface nitrate species formed during NOX activation on supported oxometallic TMI clusters A. ADAMSKI¹, M. FIUK¹, M. TARACH¹, P. ZAPAŁA¹, B. GIL¹, Z. SOJKA¹ ¹ Faculty of Chemistry, Jagiellonian University, 3 Ingardena St., PL 30-060 Cracow It is well known from earlier studies on SCR NO, mechanism that adsorption of noxious nitrogen oxides (mainly NO and NO₂) on supported clusters containing transition metal ions (TMI) may involve the formation of nitrite and nitrate species. Such forms can be stabilized over catalyst surface even up to 450-550 °C. Moreover, apperence of various nitrates can substantially lower the efficiency of NO, reduction by blocking catalytically active TMI sites. On the other hand, on basic oxides, under lean conditions, nitrates formation can be considered as a form of NO, storage. According to the generally accepted NSR mechanism, under rich conditions, nitrogen oxides can be subsequently released and efficiently reduced by hydrocarbons. Main problems can however be caused by the state of reducing agent and NO/NO₂ ratio. Even if the main steps of SCR NO, and NSR processes are alredy established, elucidation of the detailed redox mechanism accompanying NO, adsorption on supported oxometalic clusters, determination of experimental conditions favoring the formation of various surface entities and influencig their stability during oxidation and reduction cycles is still far from the final solution. There is a distinct gap in the state of our knowledge concerning the behavior of nitrites and nitrates formed during NO, activation under consecutive hydrocarbon/oxygen rich/lean conditions. The key point is related to the factors governing their reducibilily, which seems to be decisive for reversible character of nitrites/nitrates formation and thus for sucessful NO, removal. Present investigations on NO and NO₂ adsorption performed on bare and TMI-modified zirconia and ceria may serve as model studies establishing a link between changes of structural properties induced by support oxide doping with TMIs and ability of a catalytic system to efficiently store and reduce NO, under reactive atmosphere of variable hydrocarbon/oxygen ratio. EPR/IR results obtained after NO,, O₂ and HC adsorption on a series of TMI-functionalized zirconia samples, containing nominally 0.2-5.0 mol. % of aliovalent additives (Mn²⁺/⁴⁺, Sm³⁺, V⁴⁺/⁵⁺ and Mo⁵⁺/⁶⁺), were confronted to those obtained for selected ceria- and Ce,Zr!.,O₂-supported systems. TMI-doped samples were prepared by wet impregnation of the supports with aqueous solutions of the corresponding salts. All investigated samples calcined at 600°C/6h were structurally characterized by means of XRD and RS techniques. The gaseous reactants, were adsorbed at pressures of 2-20 Torr (non-equilibrium conditions) on the samples previously outgassed under vacuum at p < 10'⁵ Torr and activated at 350-400 °C for 0.5 h. Samples were contacted with gaseous adsorbates at LNT for 2 min and next exposed to room or elevated temperatures (Fig. 1). 107 NOEA2011 Zakopane 4-7 September 2011 Figure 1. Progress of NO activation during exposure of various TMI-modified ZrO₂ (5 mol. %) samples to RT, monitored by EPR. Adsorption of 10 Torr of NO over bare t-ZrO₂ at LNT resulted in relatively weak chemisorptions of NO molecules accompanied by the formation of (Zr-NO)¹ surface mononitrosyIs. as it can be inferred from the presence of the well resolved three line hyperfine structure visible in the EPR spectrum of N0/t-ZrO₂. Observed signals were however not observed in the spectra of TMI-doped samples (5 mol. %), because of the overlapping of much more intense signals from the paramagnetic V⁴* (3d¹), Mos⁺(4d‘), and Mn"⁺ ions. Observed modes of NO adsorption distinctly reflected structural and redox properties of investigated TMI/r-ZrO₂ samples. Three cases can be distinguished here: i) NO physisorption (5SmOₓ/ZrO₂), ii) weak chemisorption without electron transfer (5MnOₓ/ZrO₂) and iii) reductive adsorption - (5MoOₓ/ZrO₂ and 5VOₓ/ZrO₂). Low-temperature contact of the 5MoOₓ/ZrO₂ and 5VOₓ/ZrO₂ catalysts with 10 Ton of NO led to distinct changes in intensities of the EPR spectra without not accompanied by any new spectral features. Observed effects can be explained by the progressive reduction of V(V) and Mo(VI) centers by NO molecules via ligand to metal electron-transfer (LMET) according to the equations: NO (²n₁/₂) + Mo⁶* (‘Sₒ) = ^-{Mo^-NOJ¹ and NO (²n₎c) + V⁵⁺('S₀) = t]'-{ V⁴⁺-NO)‘ Parallel IR experiments confirmed that low-temperature (-120 °C) adsorption of 5-10 Ton of NO on 5Mo/Zr and 5V/Zr followed by exposure of these samples to RT, resulted in the formation of surface nitrates of bridging and chelating structure. NOX storage seems to be thus possible over these two TMVZtO₂ catalysts. Reducibility of the observed nitrate species was subsequently verified in the reaction with selected hydrocarbons adsorbed at LNT or RT. 108 109 Figure 2. EPR spectra reflecting redox cycle for MoO/t-ZrO₂ System Concerted action of both oxidative (O₂) and reducing agents (NO,, propene), strongly modifying redox state of TMI surface sites, can be in more detail illustrated with an example of MoO,/Zr0₂ samples (Fig. 2). Adsorption of NO led to partial reduction of the Mo(VI) to Mo(V). Subsequent propene adsorption was responsible for the reduction of the remaining Mo(VI) centers, as it can be inferred from increase of intensity of the previously observed signal. Reduction of surface molybdenum was however reversible. Consecutive O₂ adsorption caused reoxidation of Mo sites. Simultaneously, the appearance of the new signal, ascribed to O₂~ radicals, was observed. Introduction of the next portion of NO reacting with surface complexes resulted in nitrates formation, according to the eqation: (Mo^-O/I¹ +NO(²n)-> (Mo^-NO, )¹. If these nitrates were not reduced by the next portion of hydrocarbon, catalytic cycle cannot be closed. This step is vital also for NSR, where the target reduction product is nitrogen. The role of nitrates is thus crucial for catalyst performance and rejuvenation and therefore these aspect was particularly stressed in our studies. The research was partially carried out with the equipment purchased thanks to the financial support of the European Regional Development Fund in the framework of the Polish Innovation Economy Operational Program (contract no. POIG.02.01.00-12-023/08). NOEA2011 Zakopane 4-7 September 2011 NOEA 2011 Zakopane 4-7 September 2011 PS02 Comparison between Cs-Cu/ZrCh and Cs-Co/ZrCh catalysts for NOX reduction in the presence of toluene A. AISSAT¹³ D. COURCOT¹³, S. SIFFERT¹³* ¹ Univ Lille Nord de France, F-59000 Lille, France ² ULCO, UCE1V, F-59I40 Dunkerque, France ★Corresponding author: siffert@univ-littoral.fr, Tel.: +33-328658256 (S. Siffert) Industries using combustion processes are often faced to nitrogen oxides (NOX) emissions problems [1,2], A catalytic treatment by hydrocarbons may be an advantageous route for the purification of such effluents [2]. The use of zirconia (ZrO₂) and transition metal oxide phase are known to be powerful for NO, reduction [3] and also for hydrocarbons oxidation[4,5]. In some cases, alkali metals are known to be activity promoters for hydrocarbons oxidation as well as for NO; reduction [3], Cu and Co do not present the same behaviour towards NO; reduction. The effect of the alkali metal content (cesium) was studied on the physicochemical characteristics of ZrO₂ and their catalytic properties in reduction of NO; by hydrocarbons. ZrO₂ support was prepared by a precipitation method. After drying at 115°C for 24 h, this solid was calcined under air flow (2 Lh¹) at 300°C for 4 h. Cs-Cu/ZrO₂ or Cs-Co/ZrO₂ solids were then prepared by impregnation of CuCO₃ nCu(OH)₂ or CoCO₃-nH₂O salts respectively or co-impregnation of Cs₂CO₃ and the corresponding salt onto ZrO₂. After drying, the samples were calcined under air flow at 600°C for 4 h. The as-obtained solids were denoted Csₓ-Cuy/ZrO₂ or CS;-Coy/Zr0₂, where x (0.015 or 0.03) corresponds to Cs/Zr atomic ratios and y (0.1 or 0.2) Cu/Zr or Co/Zr atomic ratios. The catalysts were characterized by many techniques (BET surface areas, XRD, TG-DTA, TPR, FT1R). The reduction of NO; was carried out in a continuous flow reactor (900 ppm of NO/N₂, 1000 ppm toluene and 10%O₂/N₂, lOOmLmin¹). Before each activity test, the catalyst (lOOmg) was dried in air (2Lh', rCmin'¹) at500°C for 4 h. The volume hourly space velocity (VHSV) was 105 000 h'¹. TPR results for Cs-Cu/ZrO₂ catalysts showed that the CuO reduction signal is between 100 and 220°C with Cuoj/ZrO₂ [6]. This temperature interval increases with increasing the Cs amount. Thus, the presence of Cs decreases Cu reducibility attributed to the copper-cesium interaction. For Cs-Co/ZrO₂ catalysts (Fig. 1) several peaks are shown. Species responsible for peaks below 400°C would be small particles of Co₃O₄ on solid surface. However, for peaks beyond 500°C, the species would be attributed to zirconate cobalt. Results of NO; reduction by toluene (Table 1) demonstrate that the copper based copper solids are more active. However, in the absence of toluene (Fig. 2(A)), the cobalt based solids produce more of NO₂ (which is reduced to N₂ after toluene oxidation). Whereas, in the presence of toluene (Fig. 2(B)), the conversion of NO; is more important for Cu-based solids. This shows that produced NO₂ is reduced to N₂on Cs-Cu/ZrO₂ solids and to NO on Cs-Co/ZrO₂ ones. Ill Ill NOEA 2011 Zakopane 4-7 September 2011 Catalyst M = Cu M = Co CsM3-Mo. JZrOi 36.5 (288°C) 17.2 (308°C) Cs «. o/s-M,J/rO2 50.0 (390°C) 27.1 (389°C) M„.,/Zr()2 46.4 (410°C) 32.8 (200-350°C) Csm3-Mn2/'ZrO2 40.0 (277°C) 30.0 (282°C) Cs0.0is-MO2/ZrO2 50.2 (276°C) 22.30 (304°C) M02/ZrO2 47.5 (290°C) 25.8 (305°C) 112 NOEA 2011 Zakopane 4-7 September 2011 Figure 2. Outlet concentration of NO and NO₂for Cs₀0is-Cu₀i/ZrO₂ and Cso.oi5-Coo.i/Zr0₂ catalysts: (A) blank test without toluene, (11) test in the presence of toluene (a: NO₂, b: NO and c: NOX). The “Nord-Pas de Calais" Region, the “Syndicat Mixte de la Cote d’Opale” and European Union via Interreg IV "Redugaz project" are gratefully acknowledged for financial support. 111 T. Holma, A. Palmqvist, M. Skoglundh, E. Jobson, Appl. Catal. B 48 (2004) 95 [2] V.l. Parvulescu, P. Grange, B. Delmon, Catal. Today 46 (1998) 233 [3] A. Bueno-I.opez, J.M. Soriano-Mora, A. Garcia-Garcia, Catal. Commun. 7 (2006) 678 [4| 1). Pietrogiacomi, I). Sannino, S. Tuti, P. Ciambelli, V. Indovina, M. Occhiuzzi, F. Pepe, Appl. Catal. B 21 (1999) 141 [5] M. Haneda, Y. Kintaichi, M. Inaba, H. Hamada, Catal. Today 42 (1998) 127 [6] A. Aissat, D. Courcot, R. Cousin, S. Siffert, Catalysis Today DOI: 10.1016/j.cattod.2011.01.033 (2011) 113 NOEA20I1 Zakopane 4-7 September 2011 PS03 On the influence of exhaust gas composition for the selective reduction of NOX over Fe/ZSM-5 catalyst D, ADOUANE¹, J. STARCK¹, P. Da COSTA¹, X. JEANDEL² ¹ Universite Pierre et Marie Curie (Paris VI), Laboratoire de Reactivite de Surface - CNRS UMR 7609, 4 Place Jussieu, 75252 Paris 05, France; e-mail: patrick.da_costa@upmc.fr ² Technocentre Renault, I avenue du Golf, 78288 Guyancourt Cedex Nitrogen oxides (NO,) which are mixtures of NO and NO₂ are produced by Diesel combustion and industrial processes, and contribute to different atmospheric pollution phenomena such as ozone depletion, smog and acid rains [ I ]. In recent years, great efforts have been shown by the car manufacturer in order to reduce the ecological impact of their vehicles by developing different technologies to limit emission of such air pollutants. One of the most efficient technologies is the so called NH₃-SCR (selective catalytic reduction of oxides with ammonia as a reducing agent). Several reactions occur over SCR catalysts during the reduction of NO, with NH₃. The main reaction of SCR with ammonia which is well known as “standard SCR reaction” is [2-3]: 4NH₃ +4NO + O₂ —> 4N₂+6H₂O (1) The reaction with equimolar amounts of NO and NO₂“fast-SCR” reaction is much faster than the main reaction (I): 4NH₃ + 2NO + 2NO₂ -r 4N₂ +6H₂O (2) These theoretical reactions must be taken in account without omitting that real conditions we meet in the exhaust gas are very complex. Gas exhaust includes, among others, water, carbon monoxide and unburned hydrocarbons. Very active SCR catalysts have been reported in the literature but the problem of deactivation under high temperatures and water [4-5] or poisoning by hydrocarbon coking [6-7] still remains unsolved in most cases. To meet the durability requirement of DeNO, catalysts, an improved understanding of the impact of chemical deactivation on catalyst activity for this application is needed. The aim of this work is to study the influence of the exhaust gas composition, such as the presence or the lack of water and hydrocarbon, on the SCR catalysts efficiency. The effect of NH₃/NO, ratio on the NO, reduction was also investigated. Catalytic tests were carried out on active phase and monolith (carrots). Commercial SCR honeycomb monolith catalyst consisted on Fe-ZSM5 coated on a cordierite monolith. The monolith was crushed in order to evaluate metal contents by elementary analysis. The catalyst was characterized by X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM). Before runs and characterization, the monolith was calcined in industrial air at 500°C for 2 h, using a heating rate of 10°C min-¹ The active phase was extruded and two types of experiments were performed: 1. On active phase; 2. On monolith. Tab.l. Experimental conditions GSHV Total flow Catalyst volume Active phase 90 000 (h-1) 250 (cc/min) 0.17 (cm3) Monolith 90 000(h-l) 10 L/min 6.67 (cm3) 115 NOEA2011 Zakopane 4-7 September 2011 The different characterizations showed that iron is essentially present under oxidised form (Fc₂O₃ and a part of Fe₃O₄) and located outside and on the border of zeolithe particles. We can-not exclude the presence of cationic iron in the zeolithe channels. Water effect was investigated on this commercial catalyst. An inhibitor effect of water only for temperatures higher than 220°C was observed. This phenomenon could be explained by a better oxidative capacity of ammonia in the absence of water and an adsorption competition between water and ammonia. The effect of hydrocarbons on NOx conversion was also investigated. Catalytic tesLs were performed over washcoat and monolith in the presence of propene, decane and toluene as a representative mixture of exhaust gas. The presence of decane in the feed inhibits NOX conversion and leads to a coke deposit formation [8]. The same phenomenon was observed on monolith with toluene. The presence of propene leads to a slightly loss of performance (about a few percents) at low temperature. The influence of NH₃/NOX ratio on NOX conversion has been studied. The results confirm the impact of NH^NO,, ratio on NOX conversion. The NH^O, ratio = 1.2 leads to a higher conversion compared to NH₃/NOX ratio = 1 or 0.8 on both active phase and monolith. [ 1 ] S. Roy, M.S. Hegde, G. Madras, Appl. Enr. 86 (2009) 2297 [2] M. Devadas, O. Kro'cher, M. Elsener, A. Wokaun, N. Sóger, M. Pfeifer, Y. Demel, L. Mussmann, Appl. Catal. B 67 (2006) 187 [3] M. Koebel, M. Elsener, M. Kleemann, Catal. Today 59 (2000) 335 [4] J. N. Armor, Catal. Today 26 (1995) 147 [5] L. Gutierrez, M. A. Ulla, E. A. Lombardo, A. Kovacs, F. Lónyi, J. Valyon, Appl. Catal. A 292 (2005) 154 [6] S. Isarangura, N. Mongkolsiri, P. Praserthdam and P.L. Silveston, Appl. Catal. B 43 (2003) I [7] C. He, Y. Wanga, Y. Cheng, C. K. Lambert, R. T. Yang, Appl. Catal. A 368 (2009) 121 [8] V. Sanchez-Escribano, T. Montanari, G. Busca, Appl. Catal. B 58 (2005) 19 116 NOEA201I Zakopane 4-7 September 2011 PS04 DRIFTS-MS studies of NO reduction and NH3 oxidation over V-O-V catalyst B. AZAMBRE¹, J. BANAŚ², M. NAJBAR² ¹ Laboratoire de Chimie et Methodologies pour I’Environnement, Universite de Metz, Rue Victor Demange, 57500 Saint Avoid, France ² Faculty of Chemistry, Jagiellonian University, 3 Ingardena St., 30-060 Krakow, Poland, e-mail: mnajbar@ chemia, uj.edu.pl The anatase supported V-O-W catalysts are commonly used for selective NOK reduction (SCR) to nitrogen by ammonia [I]. Vanadia species are thought to be active in this reaction [1-3], Ammonia adsorption on acidic OH groups, formed as a result of the dissociative water adsorption is most frequently considered as the first step of this process [2,3]. However, coordinative ammonia adsorption is also considered as a first step of SCR [1]. Miyamoto et al. [2] and Topspe et al. [3] have assumed that SCR including ammonium ion formation goes on the basal (001) V₂O₅ surface [4]. However, Gąsior at al. [5] have revealed its the highest rale on the side faces of vanadia crystallites. Moreover, Anderson [6] has shown that dissociative water adsorption resulting in OH groups formation does not occur on (001)V₂0₅ face but it proceeds easily on some side crystallite surfaces. Broclawik et al. [7] have demonstrated, by DFT calculations, that the water dissociation cannot proceeds on (001)V₂0₅ surface. According to Yin DFT results [8], water adsorbs on vanadyl oxygen of (001)V₂0₅ surface by hydrogen bonding. On the other hand, the (001) V₂O₅ monolayer depleted of vanadyl oxygen and/or vanadium in the interstitial position of W-0 or Mo-0 structures shows some activity in a direct NO decomposition to nitrogen and oxygen [9-12] al temperatures 150-200°C. At higher temperatures the dissociative oxygen adsorption, resulting in recovery of the vanadyl oxygen at the surface retards NO decomposition. Thus, the consumption of vanadyl oxygen in ammonia oxidation should facilitate coordinative ammonia adsorption as well as NO decomposition. The structure of the vanadia species on the surface of titania supported vanadia-based catalysts strongly depends on their thermal pre-treatmenl [1-3, 9-14]. The (001)V₂0₅ monolayer species being in equilibrium with vanadium in the surface interstitial positions of the V-W oxide bronze are formed during the calcination of the precursor of the catalyst at 460°C [14]. However, calcination at temperatures equal or higher than 520°C [13] causes the formation of the V₂O₅ nanocryslallites crystallites besides monolayer and interstitial vanadium atoms on the catalyst surface. The first aim of this paper was to find the most active places for coordinative and cationic ammonia adsorption on the rutile supported V-O-W catalyst exposing interstitial vanadium atoms as well as monolayer and crystalline vanadia species. The second aim was to determine the activity of both the ammonia ad-species in the interaction with gaseous nitric oxide at the lowest possible temperature and to check possibility of the direct NO decomposition al this lemperalure on the surface interstitial vanadium atoms or the reduced vanadia monolayer species. The active sites for coordinative and cationic ammonia adsorption on the V-O-W catalyst exposing both nano crystalline and vanadia species and surface interstitial vanadium atoms in V-W oxide bronze were determined and their activity in NO reduction was estimated. The NHᵣTPD at a 30-410°C range was followed by DRIFTS-MS. After cooling to 150° C NO reduction by ammonia ad-species was investigated. Coordinative ammonia adsorption on main (001) surfaces of vanadia nanocrystallites and ammonium ions formation on OH groups on their side surfaces was observed. The ammonium oxidation by molecular oxygen above 230°C and lack of similar oxidation of coordinative ammonia up to 320°C was revealed. 117 NOEA2011 Zakopane 4-7 September 2011 On the contrary, coordinative ammonia species showed higher activity in NO reduction at 150 °C than ammonium ions did. The observed differences in the activity of both the ammonia ad-specics in O₂ and NO reduction were ascribed to the differences in mechanisms of (hose reactions. A direct NO decomposition was found to proceed on vanadium atoms in surface interstitial positions of V-W oxide bronze. [ 1 ] P. Forzatti, Appl. Catal. A 222 (2001) 221 [2] A. Miyamoto, K. Kobayashi, M. Inomata, Y. Murakami; J. Phys. Chem. 86 (1982) 2945 [3] (a) N. Y. Topspe; Science 265 (1994) 1217; (b) N. Y. Topspe, J. H. Dumesic, H. Topspe, J. Catal. 151 (1995) 226; (c) N. Y. Topspe, J. H. Dumesic, H. Topspe, J. Catal. 151 (1995) 241 [4] ASTM Card 9-387, Nat. Bur. Standards Circ. 539 (1958) 66-67 [5] M. Gąsior, J. Haber, T. Machej and T. Czeppe, J. Mol. Catal. 43 (1988) 359 [6] A. Andersson, J. Solid State Chem. 42 (1982) 263 [7] E. Brocławik, A.Góra, M. Najbar; J. Mol. Catal. A 166 (2001) 31 [8] X. Yin, A. Fahmi, H. Han, A. Endou, S. Salai Cheettu Ammal, M. Kubo, K. Teraishi, A. Miyamoto, J.Phys.Chem.B 103(1999) 3218 [9] M. Najbar, A. Białas, J. Camra, B. Borzęcka-Prokop, Proc. 1st World Congress on Environmental Catalysis, Societa’ Chimica Italiana, Roma, 1995, p. 283-286 [10] M. Najbar, J. Banaś, J. Korchowiec, A. Białas, Catal. Today 73 (2002) 249 [11] J. Banaś, V.Tomaśić,A. Wesełucha-Birczyńska, M. Najbar,Catal.Today 119(2007) 199 [12] J. Banaś, A. Wesełucha-Birczyńska, J.Camra, B. Borzęcka-Prokop, M. Najbar, Pol. J. Environ. Stud. 15 6A(2006) [13] A. Białas, B. Borzęcka-Prokop, A. Wesełucha-Birczyńska, J. Camra, M. Najbar, Catal. Today 119 (2007) 194 [14] M. Najbar, A. Góra, A. Białas, A. Wesełucha-Birczyńska, Solid State Ionics 141-142 (2001)499 118 NOEA2011 Zakopane 4-7 September 2011 PS05 SEM -EDS studies of transition metal catalysts for NO decomposition E. BIELAŃSKA¹, M. ZIMOWSKA¹,1. NAZARCZUK², M. KOZICKI², M. NAJBAR² ¹ Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences,8 Niezapominajek St., 30-329 Krakow, Poland ² Faculty of Chemistry, Jagiellonian University, 3 Ingardena St., 30-060 Krakow, Poland DeNO, is the most important aspect of environmental catalysis. NO interaction with the human respiratory system becomes dangerous at concentrations higher than 40 ppm and results in suffocation at a concentration higher than 500ppm. Therefore abatement of NO emission is one of the is a great challenge for the environmentalists. The selective catalytic NO reduction by ammonia to dinitrogen and water is at present commonly used for NO emission abatement from stationary sources. There is a big effort to find a catalysts for a direct NO decomposition or for a reduction of NO by a reducer cheaper, not corrosive and more friendly for environment than ammonia. It was noticed recently in our laboratory that oxide Fe-Cr-Ni system, formed on the acid-resistant austenitic steel supports during thermal cycles composed of termo-programed heating of the support followed by annealing at the final temperature shows high activity in direct NO decomposition as well as in NO reduction by carbon present in the off gases of power plants. Physico-chemical characterization of Fe-Cr-Ni oxides was performed using oxide samples striped from the steel support. X-ray powder diffraction and selected area electron diffraction were used to determine phases present in oxide Fe-Cr-Ni catalyst. The chemical composition of its surface nanolayers was determined by X-ray photoelectron spectroscopy. Scanning electron microscopy (SEM) with X-ray energy dispersive spectroscopy (EDS) allowed to determine chemical composition of particular particles from the surface microlayers of the catalyst and to localize carbon particles in the dust. This paper presents the results obtained by SEM-EDS methods. The measurements were done using high resolution field emission Scanning Electron Microscope JEOL JSM-7500F with INCA Oxford Instrument EDS system. In Fig. 1 a BSE-COMPO image (a) of a typical area of the sample composed of the dust mixed with Fe-Cr-Ni oxide catalyst (dust:catalyst weight ratio equal to 4) - grown on the surface of the tube made of an acid-resistant austenitic steel 1H18N9T/1.45 41 in the course of several thermal cycles is presented. The cycles were composed of a thermo-programmed heating in air up to 840°C with the rate of 4°/min followed by annealing at 840°C for 4 h. Figures l(b-e) contain characteristic x-ray maps of C, Fe, Cr and Ni in the surface micro-layers of that Fe-Cr-Ni oxide catalyst. The semi-quantitative chemical analysis in the micro-layer of the presented area (a) of the sample reveals the presence of: 34at.% C, 26.6at.% Si, 16.4at.% Al, 11,4at% Fe, 3at% Ca, 2.7at.% K, 1.9 at.% Mg, 1.5at.% Cr, 1.4 at.% Na and 0.8 at.% Ni (the sum of carbon, silicon and metals was taken as a 100%) Comparison of the Fe, Cr and Ni distributions in the particles of the catalyst (clear ones in the down part of Fig. la) allows to reveal the presence of the iron oxide almost free of Ni and Cr ( e.g. the biggest light particle in the left bottom part of figures ) as well as mixed Fe- Cr -Ni oxides with low content of Cr and high of Fe and Ni (e.g. three light particles in the right bottom parts of Figs a, c, d and e) or relatively high content of Cr as well as of Ni and low content of Fe (e.g. small particles close to a center of images). This results are in a good agreement with those obtained by diffraction methods and allow for their better understanding. Comparison of the COMPO image with C mapping allows to notice the presence of the shadow from the carbon particles on a inorganic part of the dust. The carbon particles positions has fundamental role in discussion of the mechanism of NO reduction by carbon. 119 NOEA 2011 Zakopane 4-7 September 2011 Figure I . BSE-COMPO-image (a), and x-ray mapping of C (b). Cr (c), Fe (d) and Ni (e) of the mixture of the Fe-Cr-Ni oxides (formed on the surface of the tube from acid-resistant austenitic steel IH 18Ni9T/l .4541 in the course of several thermal cycles composed of thermo-programed heating, 4" C / min, followed by annealing at 84ff'C in air) and the dust collected behind the electro-filters of the biomass-coal power plant (dust: oxides weight ratio equal to 4) Publication co-financed by the European Regional Development bund under the Innovate Economy Operational Programme 2007-2013, POIG.01.01.02-12-112/09 project. 120 NOEA 20II Zakopane 4-7 September 2011 PS06 XPS studies of NI-Cr-Fe oxide catalysts for NO decomposition J. CAMRA¹, J. DUTKIEWICZ¹, M. KOZICKI¹, M. NAJBAR* ¹ Faculty of Chemistry, Jagiellonian University, 3 Ingardena St., 30-060 Krakow, Poland, Ni-Cr-Fe mixed oxides forming on the surface of austenitic acid-resistant steel supports (tubes, sheets of foil or monoliths) in the course thermal treatments in oxygen containing atmosphere were found to be active in a direct NO decomposition. a- F^Oj and spinal phase with lattice parameters close to those of NiFe₂O₄ were revealed in Ni-Cr-Fe oxide layers. However, the content of both phases and their exact chemical compositions were found to depend on: i/ a sort of the austenitic acid-resistant steel, ii/a foil thickness, iii /a rate of heating, iv/ an annealing temperature, v/ an oxygen content in the gas phase as well as vi/ a number of the thermal cycles. The activity in direct NO decomposition was also found to depend on the conditions of thermal treatment. To find correlation between the Ni-Cr-Fe oxide catalyst activity in the direct NO decomposition to nitrogen and average chemical composition of the surface nanolayers, the XPS measurements were performed for the most active catalysts. In a Table below the XPS results for the Ni-Cr-Fe oxide catalyst formed on the surface of austenitic acid-resistant 1HI8N9T/ 1.4145 steel tube (wall thickness ca 1mm) in the course of a few thermal cycles, composed of the heating with the rate of 4K/min to 650°C and next annealing at this temperature for 4h, are presented. The areas of Cr 2p₃/₂ and Ni 2p₃/₂ and Fe 2p₃/₂ peaks were used to determine cation contents in the catalyst surface nanolayers. The deconvolution of the distinctly asymmetric Fe 2p₃/₂ peak allowed to determine separately the contents of Fe³⁺ and Fe²⁺ cations. Cations Fe 2p’+ Fe 2p2+ Cr2p3+ Ni 2p2+ BE [eV] 711.1 709.4 576.5 854.2 at. [%] 22.6 39.6 27.8 10.0 Comparison of the contents of Fe, Cr and Ni in the surface nanolayers with those in microlayers (Fe - 83 at.%, Cr - 1 lat.% and Ni-7at.%) reveals a strong surface segregation of Cr and weaker of Ni during austenitic acid-resistant 1H18N9T/ 1.4145 steel oxidation. Publication co-financed by the European Regional Development Fund under the Innovate Economy Operational Programme 2007-2013, POIG.0I.0I.02-12-1I2/09 project. 121 NOEA20I1 Zakopane 4-7 September 2011 PS07 Acid-activated vermiculites as catalysts of the DeNOₓ process L. CHMIELARZ¹, M. WOJCIECHOWSKA¹, M. RUTKOWSKA¹, A. WĘGRZYN¹, A. ADAMSKI¹, B. DUDEK¹, R. DZIEMBAJ¹, A. MATUSIEWICZ², M. MICHALIK³ ¹ Faculty of Chemistry, Jagiellonian University, 3 Ingardena St., 30-060 Krakow, Poland ² The Institute of Ceramics and Building Materials, Glass and Building Materials Division, Cementowa 8, 31-983 Kraków, Poland ³ Institute of Geological Sciences, Jagiellonian University, Oleandry 2a, 30-063 Kraków, Poland Clay minerals arc very attractive materials serving for many various applications including catalysis and adsorption. There is a large group of clay minerals containing significant amount of transition metal cations, which are catalytically active in various reactions. Iron is a typical component of vermiculites, however iron ions are located mainly in the octahedral sheets of clay and therefore are not accessible for reading molecules during catalytic processes. A large number of papers devoted to acid-activation of clay minerals [e.g. 1 ] reported that this process leads to partial or complete leaching of cations (including iron ions) from the octahedral sheets of vermiculite. Acid-activation increases the specific surface area and porosity, while part of iron ions removed from the octahedral sheets is deposited on the particle surface. Therefore, such easy and cheap modification of clay minerals may result in their functionalization for catalytic processes in which iron plays an essencial role. Iron is known to be catalytically active in the process of selective catalytic reduction of nitrogen oxides with ammonia (SCR NOX) [e.g. 2], Our previous studies have show significant catalytic activation of vermiculites and phlogophiles modified with nitrous acid [3J. Therefore, the present studies were extended for the activation of vermiculite with other mineral acids. The goal was to establish the link between conditions of leaching and catalytic activity. Vermiculite (S&B Industrial Minerals GmbH) was dispersed in the 0.8 M solution of HNO₃ (or HCI or H₂SO₄) with a ratio of clay mineral mass to nitric acid solution of I g/10 cm³ and stirred at 95 °C for 2, 8 or 24 h. Then, the samples were separated by filtration, washed with distillated water, dried at I2O°C for 12 h and calcined at 600°C for 5 h. The clay samples were characterized with respect to chemical composition (XRF), structure (XRD, FT-IR, UV-vis-DRS, EPR), texture BET, morphology (SEM) and surface acidity (NH₃-TPD). The catalytic experiments (SCR NOX process) were performed in a fixed-bed flow microreactor system with a continuous analysis of reaction products (QMS). The following composition of the gas mixture was used: [NO|=[NH₃|=0.25%, [O₂|=2.5%. Helium was used as a balancing gas at a total flow rate of 40 ml/min. Acid-activation of vermiculite resulted in a partial leaching of Al³⁺, Mg²⁺ and Fe³⁺ ions from the octahedral sheets. As revealed by spectroscopic methods, a part of the components leached was deposited on the particles surface. Acid-activation significantly increased the specific surface area (from 8 m²/g to about 280 m²/g) and pore volume (from 0.02 cm³/g to about 0.25 cm³/g) but decreased the surface acidity. Acid-activation of vermiculite increased their catalytic activity in the SCR NOx process (Fig 1), however its efficiency strongly depended on the type of used acid as well as duration of the acid-activation process. Wet chemistry processes accompanying the leaching of iron ions are quite complex and can determine both the status and speciation of iron species deposited on catalysts surface, resulting in differences of catalytic activity. The highest NO conversion with a relatively high conversion to nitrogen was reached for vermiculite activated with nitric acid. The progress of the SCR NOx process was only slightly limited by the side reactions of direct ammonia oxidation at temperatures above 5OO-55O°C. Therefore, acid-activation of vermiculites seems to be a very effective and cheap method for the obtaining of the catalysts for the high-temperature SCR NOx process. 123 NOE A 2011 Zakopane 4-7 September 2011 124 NOEA 2011 Zakopane 4-7 September 2011 125 NOEA 2011 Zakopane 4-7 September 2011 Figure /. Results of SCR NOx tests for vermiculite activated with nitric acid (A), sulphuric acid (B) and hydrochloric acid (C). Authors acknowledge the Polish Ministry of Science for financial support in the frame of project N N507 426939 and S&B Industrial Minerals GmbH for montmorillonite supplying. M.R. acknowledges the financial support from the International PhD Projects Programme “MPD chemia UJ" operated within the Foundation for Polish Science MPD Programme co-Jinanced by the EU European Regional Development Fund. |l| P. Komadel, J. Madejova, in: F. Bergaya, B. K. G. Theng, G. Lagaly (Eds.), Handbook of Clay Science, Elsevier, Amsterdam, 2006, 263 [2] L. Chmielarz, P. Kuśtrowski, Z. Piwowarska. B. Dudek, B. Gil, M. Michalik, Appl. Catal. B 88 (2009)331 [3] L. Chmielarz, A. Kowalczyk, M. Michalik. B. Dudek, Z. Piwowarska, A. Matusiewicz, Appl. Clay Sci. 49 (2010) 156 126 NOEA2011 Zakopane 4-7 September 2011 PS08 Is Hydrogen the main NOX reducing agent at low temperature for a CNG 3-way catalysts? M. ADAMOWSKA¹, S. CAPELA², M. SALAUN¹, L. GAGNEPAIN³, P. Da COSTA¹ ¹ UPMC Paris 6, Institut Jean Le Rond d’Alembert, UMR 7190, 2 place de la gare de ceinture, 78210 Saint-Cyr L’Ecole, France ² GDF SUEZ, Direction de la Recherche et de I’Innovation, 361 Av. du President Wilson, B.P. 33, La Plaine Saint-Denis Cedex, France,*sandra.capela@ gdfsuez.com ³ ADEME - Departement Transports et Mobilite, 500 route des Lucioles, 06560 Valbonne, France Rigorously regulated automotive exhaust gas emissions according to standards as Euro 4 (in effect since January 1,2005) or Euro 5 (September 1,2009), demands the employment of efficient strategies for emission reduction. Natural Gas (NG), primarily composed by methane, is regarded as one of the most promising alternative fuels: natural gas engines produce lower PM than diesel and for NG combustion lower combustion temperatures are required which leads to a decrease of NOx emissions [I]. For CNG 3-way catalysts, total NO conversion can be reached by its reaction with methane at high temperature (T>300°C) [2]. However, CO and H₂ are also known by their reducing properties [2,3,4] specially at relatively low temperature. The main global reduction reactions that take place in CNG conditions are: NO + H₂ ='/2N₂ + H₂O (1) NO + CO = ‘/2N₂ + CO₂ (2) 4NO + CH₄ = 2N₂ + CO₂ + 2H₂O (3) NOx abatement at low temperature has been deeply studied in the automobile industry and, in the case of CNG vehicles, hydrogen (and CO) appears as one of the promising reducing agent capable to react with NO atT<300°C |2,5,6,7], Normally platinum is considered as the most active noble metal for such reactions: NO-CO and specially NO-H₂. The aim of this work is to study the effect on the NOx treatment at low temperature by changing the NO/H₂ ratio of simulated exhaust gas composition in synthetic gas bench scale on monolithic reactor. The catalytic tests were performed on a commercial CNG catalyst in a monolith form which dimensions are 1 inch diameter x 1,9 inches length. This catalytic converter corresponds to conventional active phases coaled on a ceramic honeycomb monolith. The metal loading of the catalyst was obtained by ICP (Induced Coupled Plasma) elemental analysis. Catalytic tests were performed on a Synthetic Gas Bench (SGB) which reaction mixture was defined as follows: 0.25% NO, 0,17% CH₄, 0,48% of O₂, 9,25% CO₂, 0,47% CO, 0,34% H₂ and 18% H₂O. This conditions lead to richness of 1,005 representative of a sparck. The GHSV was fixed at 40000h '. Different runs where performed in varying the CO/H2 ratio from 0 to 1,5. Catalyst Characterisation ICP analysis showed that the commercial catalyst presented the following composition: Table 1: Noble metals loading (%wt.) Pd Rh Pt Ce 1,40+0,05 0,05±0,02 0,09±0,03 3,07+0,30 127 NOEA2011 Zakopane 4-7 September 2011 This catalyst is high loaded on palladium and it was detected a residual loading of Rh and Pt. From TEM and XPS, one can conclude that palladium is only present in oxidized form (PdO or Pd +11). Catalytic tests In Figure 1, we presented the pollutants evolution with temperature. Both Light off plots present a similar pollutants evolution, especially from 300°C: NO and methane are completely converted in N₂ and CO₂, respectively, according to the global reaction 3 mentioned above. Figure 1. CO, NOx and CH₄ profile during temperature programmed reaction with a) 1^00=0,5 and b) 1^00=1,5 Crucial differences observed among these two tests appear between 100 and 200°C. The increase of the hydrogen amount in the exhaust gas leads to an increase of NO conversion at low temperature: using a ration H₂/CO=1,5 (Fig. lb), it is observed a total NO conversion at 160°C, assuring the role of H₂ as the main reducing agent in this temperature domain. 128 NOEA 20II Zakopane 4-7 September 2011 Comparing the results obtained during the catalytic tests and the ICP results, the presence of palladium seems to have a major importance on the NO-H₂ reaction. Recent studies have been developed concerning the NOx treatment at low temperature. Hydrogen and CO are well known as the main reducing agents acting at this temperature range, but with this catalyst, H₂ seems to be the most interesting one. However, it remains very important to check the selectivity of the NO-H₂ reaction in N₂. This work was carried out in the framework of ANR PREDIT “CARAVELLE". M. Salaun acknowledges ADEMEfor phD Grant. 11] K. S. Varde, G. M. M. Asar, SAE Paper 2001-28-0023 2001 [2] M. Salaun, A. Koaukou, S. Da Costa, P. Da Costa, Appl. Catal. B doi: 10.1016/j.apcat.2008.10.026 [3] E Dhainaut, S. Pietrzyk, P. Granger, Catal. Today 119 (2007) 94 [4] R. D. Clayton, M. P. Harold, V. Balakotaiah, Appl. Catal. B 81 (2008) 161 NOEA20II Zakopane 4-7 September 2011 PS09 Influence of the ion exchanged metal (Cu, Co, Ni and Mn) on the selective catalytic reduction of NO over mordenite and ferierite W. ĆWIKŁA-BUNDYRA¹ ¹ Department of Environmental Chemistry, University of Marie Curie-Sktodowska, 3 Marie Curie-Sklodowska Sq., 20-031 Lublin, Poland, e-mail: wieslawa.cwikla-bundyra@ poczta,umcs.lublin.pl Nitrogen oxide is produced during fuel combustion at high temperature. It is considered to be the most toxic exhaust gases. While the requirements on the purity of exhaust gases were becoming more rigorous it turned out to be necessary to look for techniques reductions of NO in exhaust gases. Catalytic reduction with hydrocarbons is believed to be the most promising way to eliminate nitrogen oxide. The main advantage of the corresponding reaction is the use of gas mixture very similar to that found in exhausts. In this paper, transition group metals (Cu, Co, Ni and Mn)-loaded zeolite are examined for the selective catalytic reduction of NO by methane. All catalysts were prepared by the ion exchange method described in the literature [1]. The content of pure metal introduced to the catalysts was measured with the XRF method. Measurements of the rates of NO reduction were carried out in a gradient less reactor based on the one described in paper [2] in the temperature range 200-500° C. The reaction rate was calculated using the equation valid for a gradient less reactor. All kinetic experiments were carried out determining isothermally the relationship between the reaction rate of NO reduction and degree of NO conversion. The reaction products were analyzed chromatographically. Table 1 lists, for all catalysts, ion exchanged metal content and the ion exchange level. Table 1. Catalyst composition and main characteristics Samples Metal loading Ion exchange level Mas ratio of Si/Al |wt %] (%) Cu-l-30-MOR 1,92 53 Co-l-30-MOR 1,80 49 Ni-l-30-MOR 1,44 40 5,8 Mn-l-30-MOR 1,08 30 Cu-l-30-FER 2,82 66 Co-l-30-FER 2,36 55 7,8 Ni-l-30-FER 2,04 48 Mn-l-30-FER 1,99 46 131 NOEA2011 Zakopane 4-7 September 2011 Figure 1. The conversion of NO (mol%) in the presence of methane on pure Co-, Cu-mordenite The reaction of reduction NO in inert atmosphere was followed by monitoring NO consumption, N₂ production and selectivity to N₂, as a function of time on stream in the temperature range 200-500°C. The catalytic results at different temperatures for the examined catalysts are shown in figure 1 132 NOEA2011 Zakopane 4-7 September 2011 Figure 2. The conversion of NO (mol%) in the presence of methane on pure Co-, Cu-ferrierite Selective catalytic reduction of NO by methane was investigated on Cu, Co, Ni and Mn ion exchanged mordenite and ferierite in the presence of excess of oxygen. The catalytic activity showed for all the catalysts increased with increasing metal content reaching a maximum of NO conversion. NO conversion increased with the reaction temperature passing through a maximum, and then decreased at higher temperatures, due to the combustion of the hydrocarbon, which reduced the amount of reductant and become dominant at higher temperatures. NO TOF for all the catalysts here prepared was analyzed at 375-500°C. It was observed that this parameter decreased with the metal content and, regardless the type of zeolite and ion exchanged metal introduced in the catalysts, all the experimental points were correlated by an unique curve. The results presented have emphasized a significant point concerning the course reduction of nitrogen oxide by methane, that the reaction mechanism is determined by the catalyst used [3.4], [1] T. Yamamoto, A. Eiadua, S. Kim, T. Ohomori, J. Ing. Eng. Chem. 13 (2007) 133 NOEA 2011 Zakopane 4-7 September 2011 [2] D. Nazimek, J. Ryczkowski, Ads. Sci.Technol., 17(1999)360 [3] H. Hamada, Catal. Today 22 (1994) 21 [4] A. Kubacka, J. Janas, B. Sulikowski, Appl. Catal. B 69 (2006) 43 134 NOEA2011 Zakopane 4-7 September 2011 PSIO Structural studies and physicochemical properties of new molybdenum peroxocomplexes with nicotinic acid A. DOBIJA¹, W. NITEK¹ ² ³ ³, W. ŁASOCHA¹*² ¹ Jerzy Haber Institute of Catalysis and Surface Chemistry PAS, Niezapominajek 8, 30-239 Cracow, Poland ² Faculty of Chemistry Jagiellonian University, Ingardena 3, 30-060 Cracow, Poland Peroxocomplexes with transition metals are an interesting group of compounds important in the processes of catalytic oxidation of alcohols, sulfides [1], epoxidation etc. In general, molybdenum compounds are important substrates in catalysts syntheses, many of which are used in air cleaning processes [2], hydrodesulfurisation, propene selective oxidation, ammoxiation, accrolein oxidation, olefin metathesis and many others. Four new molybdenum peroxocomplexes with nicotinic acid have been synthesized and characterized with the use of XRD, thermal decomposition, SEM and IR spectroscopy. Compound 1 NHCjFLCO^MoOfO^OFŁ) (see Fig. 1) crystallize in space group Pc, compound 2 2[C₅H₄NCO₂(O[MoO(O₂)₂])] ■ 2NH₄⁺ crystallize in triclinic crystal system in P-1; compound 3 2[C₅H₄NCO₂(O[MoO(O₂)₂]}] • 2C₆H6NO₂ • 2H₂O crystallize in space group P2/c; compound 4 NHC₅H₄CO₂(MoO(O₂)₂OH₂) crystallize in space group P4:22. Although, some complexes with nicotinic acid were already described in literature [3], according to published data they differ from those obtained in our laboratory. In addition, compounds described in the literature have not investigated by X-ray single crystal methods. After thermal decomposition of our peroxocompounds, nano-metric molybdenum trioxide is formed, which could also lead to significant practical and technological applications. Figure 1. a) Asymmetric unit and b) unit cell packing of peroxomolybdenum complex 1. Cell parameters a=5.416(3), b=5.350(2), c=16.976(7)A, 0=106.23(3) The research has been partly supported by the EU Human Capital Operation Program, Polish Project No. POKL.04.0101-00-434/08-00 [1] J. Nasrin, M. S. Islam. J. of Appl.Sci. 7 (2007) 597 [2] W. Łasocha, A. Rafalska-Łasocha, M. Grzywa, B. Gawel. Catal. Today 137 (2008) 504 [3] C. Djordjevic, B. C. Puryear, N. Vuletic, C. J. Abelt, S. J. Sheffield. Inorg. Chem. 2 (1988) 2926 135 NOEA2011 Zakopane 4-7 September 2011 PS11 Effect of soot on NO decomposition in O2 and SO2 presence over Ni-Cr-Fe oxide catalysts J, DUTKIEWICZ¹, S. JANIGA¹,1. NAZARCZUK¹, M. KOZICKI¹, P. KORNELAK¹, M. NAJBAR¹ ¹ Faculty of Chemistry, Jagiellonian University, 3 Ingardena St., 30-060 Krakow, Poland The main ecological problem nowadays, linked to technological boom in advanced countries, is an emission of air pollutants. Nitrogen oxides NOX arc the main air pollutants. They cause damage of a human respiratory system, acid rains, a stratospheric ozone destruction, a greenhouse effect, abatement of plant vegetation, building elevation destroying and metal corrosion. Nitrogen oxides are formed mainly by forests fires, lightning, volcanoes’ explosions and soil bacteria. The men activity linked to NOX emission is related to fossil fuel combustion (petrochemical industry, transport, energy production) and nitric acid obtainment. The main NOX component in flue gases of stationary emission sources is NO. Recently the basic process for NOX control from stationary emission sources is SCR by NH₃. This process is selective to N₂ also in oxygen presence in the feed. V^-WO^anatase catalysts are commonly used in this process. Unfortunately this process has also some drawbacks: ammonia belongs to very corrosive compounds and it is relatively expensive and poisoning; the catalysts undergo deactivation under the influence of As₂O₃ and SO₂ Another way of NO emission abatement from the stationary sources of emission is its direct decomposition. The main advantage of this process is that it does not need any reducer, so does not generate other pollutants. Il is mostly investigated over noble metals and zeolites with incorporated cuprum or cobalt ions as well as on some mixed oxide of transition metals. We have found recently that Ni-Cr-Fe mixed oxides formed during oxidation of the austenitic acid-resistant steel supports show high activity (CN₀) in the direct NO decomposition and relatively high selectivity to N₂ (SN₂). The direct NO decomposition over the Ni-Cr-Fe oxide catalysts was investigated al temperatures 150-500°C. A quartz tubular reactor with GC (Molecular Sieve 5A column and TCD detector) or quartz u-tube flow reactor with MS detector were used for catalytic tests. The contents of NO in reaction mixtures were equal to 2%, 1% and 200ppm and GHSV was close to 15000 h¹. In most of the tests 5-7.4 %O₂ was added to the reaction mixture. In several tests 200-16000 ppm SO₂ was also introduced. In a few tests the catalyst was mixed with a dust collected behind the electro-filters of the biomass-coal power plant. In a Fig. I the temperature dependences of the selectivity to N₂ in direct NO decomposition on the Ni-Cr-Fe oxide catalyst (200mg) in the reaction mixtures containing: a) 2%NO/He; b) 2%NO and 5%O₂/He; c) 2%NO and 1600ppmS0₂/He; d) 2%NO, 7,4%O₂ and 200ppmS0₂/He (0.05g of the dust mixed with the 0.200g of the catalyst) are presented. The NO conversion in all the experiments is equal to 100%. The selectivity to N₂ increases in the course of the temperature increase. The highest selectivity to N₂ (100%) is achieved for NO decomposition in 2%NO/He mixture at 250°C -350°C. The addition of oxygen to the reaction mixture causes some decrease of the selectivity to N₂ (b). A much stronger decrease of the selectivity to N₂ is caused by the addition of l600ppm SO₂ (c). If NO decomposition in the feed consisting of 2%NO, 7,4%O₂ and 200ppmS0₂ proceeds on the catalyst mixed with 50mg of the dust, collected behind the electro-filters, the selectivity to N₂ is very low at 150-300°C, rapidly increases at 350°C and reaches ca. 90% at 400-500°C. MS analysis of the products formed on that catalyst containing different amounts of the dust reveals that at 300°C oxygen oxidizes the carbon mostly to CO. Next carbon monoxide reduces NO mostly to N₂. 137 NOEA 2011 Zakopane 4-7 September 2011 Figure 1. The selectivity to N₂ in the direct NO decomposition on 200mg of the Ni-Cr-Fe oxide catalyst (a-c) or on the mixture of that catalyst with 0.05g of the dust (d) in the reaction mixtures containing: a) 2%NO/He; b) 2%NO and 5%O₂/He; c) 2%NO and lóOOppmSOfHe;, d) 2%NO, 7,4%O₂ and 200ppmS0₂/He; GHSV=15000 h¹ Publication co-financed by the European Regional Development Fund under the Innovate Economy Operational Programme 2007-2013, POIG.Ol.01.02-12-112/09 project. 138 NOEA2011 Zakopane 4-7 September 2011 PS12 Surface, structural and morphological characterization of nanocrystalline ceria-zirconia mixed oxides upon thermal aging I. DOBROSZ-GÓMEZ¹, M. A. GÓMEZ-GARCIA¹, M. I. SZYNKOWSKA², I. KOCEMBA², J. M. RYNKOWSKI² ¹ G.I.A.N.T., Grupo de Investigation en Aplicadón de Nuevas Tecnologias, Universidad National de Colombia, Sede Manizales, Colombia ² Institute of General and Ecological Chemistry, Technical University of Łódź, 90-924 Łódź, Żeromskiego 116, Poland Ceria and ceria-based materials (especially its substitutional solid solutions) have attracted much attention in recent years mainly due to their application as a crucial component of modem catalysts used for automotive emission control (TWCs). It is generally known that the incorporation of zirconium into the ceria lattice creates more defects, which can stabilize ceria against sintering, enhancing the thermal stability and the efficiency of the TWCs. In the theory, the catalytic activity is directly related to the chemical composition and the structure of the catalyst. Materials with nanocrystalline structure, characterized with high surface area and high porosity are desired for the practical applications, taking into consideration their potential kinetic advantages. Several methods have been used for the synthesis of nanocrystalline CeO₂-ZrO₂ solid solutions, including co-precipitation, direct hydrothermal synthesis, sol-gel technique, polymerized complex method, the amorphous citrate process, gel combustion, evaporation induced self-asambley (EISA), hard-template method, etc. (1,2). The obtained materials differed in the surface area, crystallite size, crystalline structure, reducibility, etc., confirming that the preparation method can strongly affect the surface and structural properties of CeO₂-ZrO₂ oxides. Moreover, some of the obtained oxides contained chlorine ion which is commonly known as a poison of three-way catalyst. It should be also noted that some of these approaches are complicated and presents limitations, which are not suitable for large scale applications. On the other hand, some of them (e.g. sol-gel and citrate complexation) do not guarantee the homogeneity of the produced materials in all compositional range (3). Therefore, reliable synthetic routes for synthesis of Ce-Zr mixed oxides as nanoparticular powders in the wide compositional range and preferably via low-energy chemical steps arc required. In this work, a variant of sol-gel technique known as sol-gel like method (4) was employed to obtain nanocrystallinc, homogenous in size dimension and morphology, Ce-Zr solid solutions in a wide compositional range. It should be noted that several papers have been reported the physico-chemical properties and catalytic performance of Ce-Zr mixed oxides. However, contradictory informations can be found in the literature, especially over “the best” Ce-Zr composition in the terms of the thermal stability and redox properties: either CeO₂- or ZrO₂ rich, or Ce^Zr ₀₅O₂ has been already indicated as the most effective compositions (5-7). Herein, we present the systematic characterization of the physico-chemical properties of fresh and thermally aged Ce^Zr,^ (0 < x < 1) mixed oxides. The relationship between the surface, structural and morphological properties of the Ce/Zr molar ratio upon thermal aging was studied by means of different techniques, such as TGA-MS, N₂-BET, SEM-EDS, XRD. It was of particular interest to determine “the best composition” of CeₕₓZrₓO₂ (0 < x < 1) mixed oxides upon thermal aging, considering also its catalytic performance. In this study, CO oxidation was used as test reaction. Very homogeneous in size dimension and morphology, nanosized, Ce|.ₓZrₓO₂ (0 < x < 1) materials were synthesized by the sol-gel like method. The existence of a single cubic structure of CeO₂ and both monoclinic and tetragonal ones of ZrO₂ was confirmed. In the whole composition range, dissolution of ZrO₂ into CcO₂ lattice was observed, accompanied by the formation of a fluorite-type structure in the case of the 75/25 mixed oxide composition and tetragonal one for ZrO₂ content > 50 mol %. The formation of single phase, homogenous solid solutions was confirmed. The extent of crystallite agglomeration was increasing gradually with ZrO₂ substitution in Ce0₂-ZrO₂ solid solution powders. Upon thermal aging, the 139 NOEA 2011 Zakopane 4-7 September 2011 crystalline phases of CeᵣₓZrₓO₂ (0 < x < 0.75) powders remain unchanged. Only for ZrO₂, the transformation of t-ZrO₂ into m-ZrO₂ was observed. No phase segregation for Ce!.ₓZrₓO₂ mixed oxides into a CeO₂-rich and ZrO₂-rich mixture was detected, indicating the presence of compositionally homogenous solid solutions. A strong effect of the samples composition on their specific surface area (SBet) >s observed. The values of SBEᵣ were decreases in the following order: CeO₂ > CcojsZro^Ą > Ceo5Zr₀₅0₂ > Ceo.₂5Zro7₅0₂ > ZrO₂. Upon thermal aging, a lower decrease in the surface area of CeO₂-ZrO₂ mixed oxides compared to pure oxides is observed, confirming the preventing role of ZrO₂ addition into CeO₂ in the sample sintering. The strong effect of the oxide composition on the sintering of Ce|.ₓZrₓO₂ oxides is observed. The lowest sintering effect was detected in the case of the 75/25 mixed oxide composition. The specific activity of CeO₂-ZrO₂ mixed oxides in CO oxidation was found to be dependent on Ce/Zr molar ratio. The 75/25 solid solution composition shows the highest specific activity among the studied oxides. The significant effect of the average crystallite size on the oxide catalytic performance is observed. The lower the crystallites size the solid contains, the higher is the activity in CO oxidation. The influence of the presence of small agglomerates on the specific activity of Ce|.ₓZrₓO₂ oxides was detected. The higher amount of agglomerates the solid contains, the lower is the activity in CO oxidation. The incorporation of ZrO₂ into CeO₂ lattice enhances both ils resistance against sintering and its catalytic performance, especially as long as cubic symmetry of mixed oxides is maintained. Higher surface area, the presence of smaller particles and a lower amount of particles agglomerates generate a better catalytic performance of Ce|.ₓZrₓO₂. Those oxides exhibit a higher amount of crystal faces, edges, and comers, conventionally considered as active sites for the adsorption of reactants in comparison to the sintered powders. [ 1 ] R.O. Fuentes, R.T. Baker, J. Phys. Chem. C 113 (2009) 914 and references therein [2] Ch. Li, X. Gu, Y. Wang, Y. Wang, Y. Wang, X. Liu, G. Lu, J. Rare Earths 27 (2009) 211 and references therein [3] M. Alifanti, B. Baps, N. Blangenois, J. Naud, P. Grange, B. Delmon, Chem. Mater. 15 (2003) 395 [4] H. Provendier, C. Petit, J.-L. Schmitt, A. Kiennemann, C. Chaumont, J. Mat. Sci. 34 (1999) 4121 [5] H. Vidal, J. Kaspar, M. Pijolat, G. Colon, S. Bernal, A.M. Cordon, V. Perrichon, F. Pally, Appl. Catal. B 27 (2000)49 [6] A. Trovarelli, C. de Leitenburg, G. Dolcetti, Chemtech 27 (1997) 32 [7] M. Fernandez Garcia, A. Martinez Arias, A. Iglesias Juez, C. Belver, A.B. Hungria, J.C. Conesa, J. Soria, J. Catal. 194(2000)385 140 NOEA 2011 Zakopane 4-7 September 2011 PS13 Nanostructured Co-Ce-O systems for catalytic decomposition of N2O R. DZIEMBAJ¹, M. M. ZAITZ¹, M. RUTKOWSKA¹, M. MOLENDA¹, L. CHMIELARZ¹ ¹ Faculty of Chemistry, Jagiellonian University, 3 Ingardena St., 30-060 Krakow, Poland Nitrous oxide (N₂O) presents in air has come from both natural and antropogenic emission. The major sources of this emission are chemical industry (e.g. production of nitric acid, adypic acid, caprolactam, glyoxal), agricultural soil management, animal manure management, sewage treatment and combustion of fossil fuels. N₂O is considered as a strong greenhouse gas with very high (near 300 times larger than an equal mass of CO₂) global warming potential. Nitrous oxide is also known to take part in the catalytic destruction of the stratospheric ozone succeeding its photolytic oxidation to nitric oxide (NO). It is estimated its almoust linear increase of 0,26% N₂O per year due to emission from the human-related sources!I]. One of the most promisful way of reduction of N₂O emission is its catalytic decomposition to nitrogen and oxygen. Two series of nanostructured materials were prepared using a modified reverse microemulsion method [2], The first series was composed of ceria nanograins doped with cobalt ions, while the other was based on cobalt spinel doped with cerium ions. The obtained precursors were subjected to thermal analysis (EGA-TGA/DTG/SDTA) in order to determine optimal calcination temperature. The crystal structure and phase characterization of the powders was determined from XRD measurements, supported with the scanning electron microscopy (SEM). Elemental analysis of the catalysts were performed using the optical emission spectroscopy with inductively coupled plasma (ICP-OES). Surface morphology, specific surface area and pores distribution were evaluated on the basis of the BET method. 141 NOEA 2011 Zakopane 4-7 September 2011 Figure / The catalytic decomposition of N₂O on a) Ce/ ₓCoₓO₂₃ and b) cobalt spinels All the ceria doped materials formed mono phase solid solutions, showing a fluorite-like structure. The second group of materials, cobalt spinel doped with cerium ions, formed core-shell type grains with distinctly separated two phases of the cobalt spinel covered with thin layer of ceria. All the materials (from both series) were tested as catalysts in N₂O decomposition showing high activity hut those based on the cobalt spinels (binary phase grains) showed better catalytic performances in N₂O decomposition. The differences in catalytic activity of these two series of the catalysts were discussed in relation to their crystal and electron structure. Acknowledgement: This work was supported by Research Project Grant number N N209 099337, from the Polish Ministry of Science and Higher Education. The part of the measurements was carried out with the equipment purchased thanks to the financial support of the European Regional Development Fund in the framework of the Polish Innovation Economy Operational Program (contract no. PO1G.02.01.00-12-023/08). [1] S. Surinder, Agriculture, Ecosystems & Environment, 136(2010) 1X9 [2] R. Dziembaj, M. Molenda, L. Chmielarz, M. Drozdek, M. M. Zaitz, B. Dudek, A. Rafalska-Łasocha, Z. Piwowarska, Catalysis Letters, 135 (2010) 68 142 NOEA201I Zakopane 4-7 September 2011 PS14 Membrane reactor for ammonia decomposition - design guides M. A. GOMEZ-GARCIA¹.1. DOBROSZ-GÓMEZ¹, J. FONTALVO¹, J. M. RYNKOWSKI² ¹ G.I.A.N.T., Grupo de Investigation en Aplicación de Nuevas Tecnologtas, Universidad National de Colombia, Sede Manizales, Colombia ² Institute of General and Ecological Chemistry, Technical University of Łódź, 90-924 Łódź, Żeromskiego 116, Poland Air pollution, due to the use of fossil fuels for power generation, is one of the main environmental problems of the 21 st century society [1], For NOX emissions control from stationary sources, various alternatives are available today. Selective Catalytic Reduction (SCR) technology is a current large-scale commercial practice. The main chemical reaction for NOX SCR process is: 4M9+4NH₂ + O₂ <=> 4/V₂ + 6H₂O (1) In fact, the industrial control of NO removal in commercial units can be accomplished by injecting of the required amount of NH₃ to the flue gases. Typically, in a SCR process, 1-1.5 m³ of catalyst is required for each megawatt of electric power generating capacity while providing more than 80% of NO removal [2], Characteristic operating temperatures are in the range 600 - 900 K, and gas space velocities (GHSV) are in the 2000 - 7000 h'¹ (STP) range [3], Besides its known advantages, SCR technology has several important drawbacks. One of the most important is related with the ammonia slip. The more tightening environmental regulations obligate to improve the actual SCR technology while keeping its outstanding features. Ammonia removal by decomposition has been proposed in the literature by different authors [4]. Since the ammonia decomposition is thermodynamically limited, a membrane reactor appears as an alternative. However, in the literature, methodologies for the analysis and design of membrane reactors have been rarely addressed [5]. In this work, a systematic approach for the feasibility analysis of a membrane reactor for the ammonia decomposition is presented. The equilibrium shift in a membrane reactor is accomplished. Pressure and sweep gas flow rate are included in the analysis (Figure 1). The effect of permeation rate, reaction rate, and selectivity on the exit conversion is also considered. Two dimensionless groups, Pe and Da, are employed to represent the relative magnitude of permeation rate and reaction rate to conversion, respectively. This allows constructing a design chart for the ammonia decomposition system (Figure 2). A mathematical model including conservation of mass in the tube and shell side of reactor is proposed. The proposed model was solved numerically and lhe effects of different parameters on the rector performance were investigated. The effects of pressure, temperature, flow rate (sweep ratio), membrane thickness and reactor diameter have been investigated in the present study. Increasing ammonia conversion was observed by raising the temperature, sweep ratio and reducing membrane thickness. When the pressure increases, the decomposition is gone toward completion but, at low pressure the ammonia conversion in the outset of reactor is higher than other pressures, but complete destruction of the ammonia cannot be achieved (Figure 3). The proposed model can be used for design of an industrial catalytic membrane reactor for removal of ammonia from ammonia plant and reducing NOX emissions. 143 NOEA 2011 Zakopane 4-7 September 2011 144 NOE A 2011 Zakopane 4-7 September 2011 Figure 3. Conversion as a function of reactor length for different feed temperatures [1] K. Schnelle, in: C. Brown (Ed.), Air pollution control technology. CRC press; N. Y., 2002 [2] A. Cybulski, in: J. Moulijn (Ed.), Structured Catalyst and reactors. Marcel Dekker, 1998 [3] J. Beeckman, L. Hegedus, Ind. Eng. Chem. Res. 30 (1991) 969 [4] M. R. Rahimpour, A. Asgari, J. Hazard. Mat. 153 (2008) 557 [5] Y-S. Huang, E-U. Schliinder, K. Sundmacher, Cat. Today. 104 (2005) 360 145 NOEA2011 Zakopane 4-7 September 2011 PS15 IR studies of the coadsorption of CO and electron donor molecules on Cu⁺ sites in CuZSM-5 zeolite K. GORA-MAREK¹ ¹ Faculty of Chemistry, Jagiellonian University, 3 Ingardena St., 30-060 Krakow, Poland Many studies have been devoted to the properties of the Cu⁺ sites in zeolite due to their catalytic activity in denox processes. It is well known that the exchangeable cations are modified by the framework oxygens as well as by the interaction with reagent molecules. The goal of the present study was to follow the ability of the Cu⁺ cations to activate the CO in the presence of the preadsorbed molecules of the different electron donor properties e.g. NH₃, pyridine, and H₂O. The sorption of CO at room temperature in CuZSM-5 results in the formation of the Cu⁺(CO) monocarbonyls (the band at 2157 cm¹) (Fig.l, spectrum a), which are easily transformed into dicarbonyls Cu⁺(CO)₂ (2178 and 2150 cm ¹)[ 1,2], The coadsorption of CO and ammonia (with the different saturation of the Cu⁺ cations with NH₃ molecules) has been followed. The ammonia molecules number interacting with one Cu⁺ site determined in the quantitative IR experiments was following NH^Cu^ 0.5, 1, 1.8. The interaction of CO with copper sites in zeolites CuZSM-5 containing NH^Cu^ 1.8 and NH^Cu^ I (Fig.l, spectrum b and c) results in the appearance of the monocarbonyl bands and Cu⁺(CO)(NH₃) and Cu⁺(CO)(NH3), ₈ at 2133 and 2100 cm'¹, respectively. The CO frequency in Cu⁺(CO)(NH₃)ₙ adducts is distinctly lower than in monocarbonyls without ammonia molecules Cu⁺(CO) (2157 cm¹). Such important CO bond activation is suggested to be realized by the electron transfer from electron donor ammonia molecules via Cu⁺ to antibonding it orbital of CO. The coadsorption of CO and pyridine (Fig.l, spectrum d) also consequences in the development of the band of the Cu⁺(CO)Py adducts (at 2085 cm¹). The red shift (Av = 72 cm'¹) from the position of the monocarbonyls Cu⁺(CO) (2157 cm'¹) is more pronounced in comparison to the rich ammonia Cu⁺(CO)(NH₃)i ₈ adducts. It means that one pyridine molecule is more effective electron donor than two ammonia molecules. The short evacuation at room temperature results in the disappearance either the Cu⁺(CO)Py (the 2085 cm'¹ band) or Cu⁺(CO)(NH₃), ₈ (the 2100 cm'¹ band) - spectra not shown - whereas the Cu⁺(CO) band (at 2157 cm'¹) does not restore. Therefore the molecules of CO are supposed to be weakly bonded into both of Cu⁺(CO)Py and Cu⁺(CO)(NH₃)| ₈ adducts, they are easily removed. The results of coadsorption of CO and H₂O (Fig. 2, spectra a - e) have been found as the most interesting. Similarly as for ammonia and pyridine, the red shifted band of the carbonyl Cu⁺(CO)(H₂O)ₙ adducts was detected. The position of this band depends on the number of water molecules bonded into Cu⁺(CO)(H₂O)„ adducts. The highest activation of CO bond was observed for maximum amount of water in CuZSM-5 (i.g. Cu⁺ cations) - the CO band at 2110 cm'¹. The lower number of H₂O molecules is, the activation of CO bond is less pronounced and the red shift of the band of Cu⁺(CO)(H₂O)„ adducts is smaller. What is interesting, the evacuation at room temperature consequences in the disappearance of the red shifted component Cu⁺(CO)(H₂O)ₙ while the monocarbonyl band Cu⁺(CO) at 2157 cm'¹ is restored (Fig. 2, spectra f - i). Contrary to the Cu⁺(CO)Py and Cu⁺(CO)(NH₃)| ₈ adducts where the CO molecules where weakly bonded to Cu⁺ cation, in Cu⁺(CO)(H₂O)ₙ complexes the water molecules are weekly bonded to Cu⁺(CO). 147 NOEA 2011 Zakopane 4-7 September 2011 Figurel. The IR spectra of CO sorbed in CuZSM-5: (a) without preadsorbed molecules, (b) containing NH/Cu* = 1, (c) containing NHj/Cu* = 1.8, and (d) with pyridine coadsorbed. Figure2. The IR spectra recorded upon the sorption of CO in CuZSM-5 without H₂O preadsorbed (a), with H₂O preadsorbed (b - e), and after the evacuation at room temperature (f- i). This study was sponsored by the Ministry of Science and Higher Education, Warsaw, Poland (project No. N N204 017039). [ 1 ] G. Hiibner, G. Rauhut, H. Stoll, E. Roduner, Phys. Chem. Chem. Phys. 4 (2002) 1073 [2] G.T. Palomino, S. Bordiga, A. Zecchina, G.L. Marra, C. Lamberti, J. Phys. Chem. B 104 (2000) 8641 148 NOEA20I1 Zakopane 4-7 September 2011 PS16 The simultaneous SCR of N2O and NOX on Co-Na-MOR using CH4 alone as the reducing agent M. C. CAMPA¹, V. INDOVINA¹’², D. PIETROGIACOMI¹,² ¹ Istituto per lo Studio dei Materiali Nanostrutturati-CNR, do Dipartimento di Chimica, "Sapienza" Universita di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy. ² Dipartimento di Chimica, “Sapienza ” Universita di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy Uhde’s proprietary EnviNOx® process performs the tail-gas abatement of N₂O and NOK over iron containing zeolite catalysis. In cooperation with Siid-Chemie, Uhde has developed special iron-exchanged zeolite catalysts for use in the EnviNOx® process [I]. Iron-containing MFI zeolites are active for N₂O abatement with various hydrocarbons (CH₄, C₂H₆, C₂H₄, C₂H₂> C₃H₈, C₃H₄) [2] and with CH₄, CO, or CH₄+CO mixtures [3], These catalysts and analogous iron-containing catalysts are poorly active for N₂O decomposition [3,4] and inactive for NOX abatement with CH₄ in the presence of excess O₂ [5]. A drawback with the iron-containing zeolites is the CO formation during N₂O or NOX abatement using hydrocarbon reducing agents [2,6-8]. Co-Na-MOR catalysts are (i) active for N₂O decomposition [4,9,10], (ii) active and selective for NOX abatement with CH₄ in the presence of excess O₂ [ 11 ], and (iii) active and selective for N₂O abatement with CH₄ in the presence of excess O₂ [12]. At variance with iron-containing zeolites, on Co-Na-MOR in the selective catalytic reduction of NO or N₂O with CH₄ no CO formed [11,12]. Because Co-Na-MOR catalysts are active for both the SCR of NOX and the SCR of N₂O with CH₄, in this paper we investigated the activity of these catalysts for the simultaneous SCR of N₂O and NOX using CHi alone as the only reducing agent. The catalyst we tested, Co-Na-MOR-9.2-104, was a portion of that we have previously characterized by FTIR, using CO or NO as probe molecules, and volumetric adsorption of CO [11-13]. In preliminary experiments, we checked that the activity of this catalyst for (i) N₂O decomposition, (ii) CH₄+N₂O, (iii) CH₄+O₂, (iv) SCR of NO with CH₄ and (v) SCR of N₂O with CH₄ matched that of the same sample investigated previously for the same reactions [11,12], The catalyst was prepared by ion-exchange of Na-MOR at 350 K by contacting a weighted amount of MOR with an aqueous solution of acetate of cobalt. To obtain this extensively exchanged sample, three exchange procedures were run in sequence. Sample is labeled as Co-Na-MOR-9.2-104, where 9.2 is the Si/Al ratio value, and 104 is the analytical metal ion exchange percentage, calculated assuming that one Me corresponded to two Al atoms. The catalytic activity for the various reactions was studied in a flow apparatus with GC analysis of reactants and products. The results show that Co-Na-MOR is active for the simultaneous SCR of N₂O and NOX using CH₄ alone as the reducing agent (Fig. 1). 149 NOEA 2011 Zakopane 4-7 September 2011 Figure I. Percent NO conversion, percent N₂O conversion and percent CH₄ conversion, as a function of temperature on Cu-Na-MOR-9.2-I04.Composition mixture/ppm : NO/N₂O/CH4/O₂ -4000/4000/4000/20000 111 Brochures of EnviNOx, are available at http://www.uhde.biz [2] M.A.G. Hevia and J. Perez-Ramirez. Environ. Sci. Technol. 42 (2008) 8896-89(X) [3] M.N. Debbagh, C. Salinas Martinez de Lecea, J. Perez-Ramirez, Appl. Catal. B 70 (2007) 335-341 [4] Y. Li, J.N. Armor, Appl. Catal. B I (1992) L2I-L29 [5] V.l. Parvulescu, P.Grange, B. Delmon, Catal. Today 46 (1998) 233-316 [6] X. Feng, and W. K.Hall, J. Catal. 166 (1997) 368-376 [7] H.-Y. Chen, W.M.H. Sachtler, Catal. Today 42 (1998) 73-83 [8] H.-Y. Chen, X. Wang, W.M.H. Sachtler, Appl. Catal. A 194-195 (2000) 159-168 |9] F. Kapteijn, J. Rodriguez-Mirasol, J.A. Moulijn, Appl. Catal. B 9 (1996) 25-64 [10] M.C. Campa, V. Indovina, D. Pietrogiacomi, Appl. Catal. B 91 (2009) 347-354 [ 11] M.C. Campa, I. Luisetto, D. Pietrogiacomi, V. Indovina, Appl. Catal. B 46 (2003) 511-522 [12] M.C. Campa. V. Indovina, D. Pietrogiacomi, Appl. Catal. B, submitted [13] V. Indovina, M.C. Campa, D. Pietrogiacomi, J. Phys. Chem. C 112 (2008) 5093-5101 150 NOEA2011 Zakopane 4-7 September 2011 PS 17 In situ FT-IR spectroscopic investigation of gold supported on tungstated zirconia as DeNOₓ catalyst M, KANTCHEVA¹, M. MILANOVA¹ ¹ Department of Chemistry, Bilkent University, 06800 Ankara, Turkey, e-mail: margi@fen.bilkent.edu.tr (M. Kantcheva) Recent investigations have shown that a combination of a noble metal and W oxide generates catalytic systems active in the SCR of NOX with CO [1,2]. Herein, we report the results of spectroscopic characterization of gold catalyst supported on tungstated zirconia. The Au/WOₓ-ZrO₂ sample was prepared by cationic adsorption using [Au(en)₂]CI₃ as the precursor (en=ethylenediamine). This method was developed first by Guillemot et al. [3] for the introduction of gold on oxide supports with a point of zero charge below 5. In order to evaluate the potential of a new material as a catalyst in the process of CO-SCR of NOX, it is important to investigate the interaction of the reactants with the surface. For that purpose we used in situ FT-IR spectroscopy to study the adsorption of CO and its coadsorption with oxygen and NO over Au-promoted and Au-free tungstated zirconia. Sample preparation. Tetragonal ZtO₂ was prepared according to the procedure described in [4]. Tungstated zirconia containing 18 wt% of WO₃ (denoted as 18WZ-CP) was synthesized by co-precipitation [5], Gold was deposited by cation adsorption from aqueous solution of [Au(en)₂]³⁺ complex at pH=9.6 and room temperature [3], Sample characterization. XRD analysis was performed on a Rigaku Miniflex diffractometer with Ni-filtered Cu Ka radiation (%= 1.5405 A). The DR-UV-Vis spectra were recorded under ambient conditions with a fiber optic spectrometer AvaSpec-2048 (Avantes) using WS-2 as a reference. The X-ray photoelectron spectra were obtained using unmonochromatized Al Ka (1486.6 eV) radiation in a VG ESCALAB MK 11 electron spectrometer. The FT-IR spectra were recorded using a Bomem Hartman & Braun MB-102 model FT-IR spectrometer with a liquid-nitrogen cooled MCT detector at a resolution of 4 cm'¹ (100 scans). The self-supporting discs (-0.01 g/cm²) were activated in the IR cell by heating for 1 h in a vacuum at 400°C, and in oxygen (100 Torr, passed through a trap cooled in liquid nitrogen) at the same temperature, followed by evacuation for 1 h at 400°C. The spectra of adsorbed gases were obtained by subtracting the spectra of the activated sample from the spectra recorded. The sample spectra were also gas-phase corrected. According to the XRD data all of the samples have the structure of tetragonal zirconia. The average size of the gold particles is around 8 - 9 nm as calculated by using Scherrer equation and the main gold diffraction line of 20 = 38.2°. The optical spectra of the Auconlaining sample indicate that gold hinders the LMCT transition (O²->Wfrt) suggesting that the gold particles are in a contact with the WOX species. According to the XPS data, the Au/18WZ-CP sample contains in addition to Au°, W(VI) and Zr(IV), some amount of W(V) and Zr(lll). The surface concentration of gold on Au/ZrO₂ and Au/18WZ-CP samples is 0.2 and 0.3 at %, respectively. 151 NOEA 2011 Zakopane 4-7 September 2011 Figure I. FT-1R spectra collected at various temperatures during the interaction between CO (10 Torr) and nitrate species adsorbed on the catalyst surfaces Fig. I displays the FT-1R spectra obtained during the interaction of nitrate species adsorbed on the surfaces of Au/18WZ-CP and Au/ZrO₂ catalysts with CO (10 Torr) at various temperatures. The surface nitrates were generated by adsorption of a (10 Torr NO +25 Torr 02) mixture at 25°C for 20 min followed by evacuation for 20 min at the same temperature. The contact of the samples containing pre-adsorbed NO< ions with CO at room temperature causes the formation of NCO species adsorbed on gold particles. In the case of the Au/18WZCP catalyst, the isocyanates disappear at 200°C simultaneously with the NO₂ that is generated in the gas phase by decomposition of the surface nitrates. The NCO+NO₂ reaction on the Au/ZrO₂ catalyst (Fig. 1) takes place at higher temperature (250°C). In the absence of CO, gaseous NO₂ over both catalysts is observed in the 25 - 250°C temperature range (the spectra are not shown). This fact supports the conclusion that NO₂ is reduced by CO with the intermediacy of Au-NCO species leading to the formation of N₂ and CO₂. Although the higher concentration of surface nitrates on the Au/ZrO₂ sample, the amounts of NCO species formed and NO₂ evolved in the gas phase are lower than those observed over the Au/l8WZCP catalyst (Fig. I). This suggests that the tungstate species decrease the stability of surface nitrates making the WOx-containing catalyst more active in the NO₃'+CO surface reaction. In addition the weak absorptions al 1450 and 1420 cm'¹ ² ³ observed in the spectrum of Au/ZrO₂ detected at 250°C (Fig. 1) indicate the formation of stable polydentate carbonates which may have negative effect on the catalytic activity. No such species are found in the case of the Au/18WZ-CP sample. The NO+CO adsorption on Au/18WZ-CP catalyst in the 25 - 250°C temperature range does not cause the formation of surface nitrates and no Au-NCO species are detected under these conditions. This result implies that the nitrate species or adsorbed NO₂ are essential for the generation of surface isocyanates and the oxidation of NO by oxygen is an important step. Finally, it should be noted that the Au-free 18WZ-CP sample does not catalyze the interaction between adsorbed nitrates and CO. The evolved NO₂ is present in the gas phase between 25 and 350°C. The results of in situ FT-IR spectroscopic investigation indicate that Au catalyst supported on lungstated zirconia could be promising in the selective reduction of NOX with CO under lean conditions. This work has been performed in the framework of a D36/003/06 COST program. The financial support ofTBAG - I09T854 Project is greatly appreciated. We thank Dr. I. Avramova for the XPS analysis. ¹ ² ³ [1] M. Shimokawabe. N. Umeda, Chem. 1 >ett. 33 (2004) 534-535 [2] M. Shimokawabe, M. Niitsu, H. Inomata, N. Iwasa and M. Arai, Chem. Ixtt. 34 (2005) 1426-1427 [3] I). Guillemot, V. Yu. Borovkov, V. B. Kazansky, M. Polisset-Thfoin, J. Fraissard, J. Chem. Soc. Faraday Trans. 93 (1997) 3587-3591 152 NOEA20I1 Zakopane 4-7 September 2011 [4] A. Adamski, P. Jakubus, Z. Sojka, Mater. Sci.-Poland 26 (2008) 373-380 [5] J.G. Santicsleban, J. V. Vartuli, S. Han, R. D. Bastian, C. D. Chang, J. Catal. 168 (1997) 431441 NOE A 2011 Zakopane 4-7 September 2011 PS18 Co-Mn-Al mixed oxide supported on T1O2 for N2O decomposition K. KARASKOVA¹, Ż. CHROMCAKOVA¹, S. STUDENTOVA L. OB ALOV A¹⁴, K. JIRATOVA³ VŚB - Technical University of Ostrava, ¹ Faculty of Metallurgy and Materials Engineering ² Centre for Environmental Technologies, 17. listopadu 15, 708 33 Ostrava, Czech Republic ³ Institute of Chemical Process Fundamentals CAS v.v.i., Rozvojova 135, 165 02 Prague, Czech Republic Catalytic decomposition of nitrous oxide is the subject of research of many groups due to its negative impact on the environment. Our previous papers deal with Co-Mn-Al mixed oxide catalyst [1]. The aim of presented work is a preparation of Co-Mn-Al mixed oxide supported on TiO₂ and evaluation of TiO₂ support effect on N₂O catalytic decomposition efficiency. Series of Co-Mn-Al/TiO₂ catalysts with different Co-Mn-Al oxide loading (1-25 wt%) were prepared by impregnation of crushed commercial TiO₂ particles (0.16 - 0.315 mm with solution of nitrate salts (Co:Mn:Al molar ratio of 4:1:1) and following drying and calcination (4 hours at 500 °C in air). Samples were assigned according to content of Co-Mn-Al oxide. For comparison, the commercial TiO₂ and unsupported Co-Mn-Al mixed oxides prepared by two different methods (Co-Mn-Al-carb, Co-Mn-Al-nitr) were used. The Co-Mn-Al-nitr catalyst was prepared by calcination of corresponding nitrates, the Co-Mn-Al-carb catalyst by mechanochemical reaction of Co, Mn, Al nitrates with NH4HCO3. All prepared samples were characterized using various techniques (XRD, N₂ adsorption/desorption measurements, TPR-H₂ andTPD-NH₃, CO₂). Catalytic measurements of N₂O decomposition were performed in an integral fixed bed stainless steel reactor of 5 mm internal diameter (300 - 450 °C, atmospheric pressure, 0.1 mol% N₂O balanced by helium, 0.1 g catalyst, GHSV 60 1 g'¹ h¹). Fraction with particle size of 0.160- 0.315 mm was used for catalytic measurements. The steady state of the N₂O concentration level was measured. The quadrupole mass spectrometer RGA 200 (Stanford Research Systems, Prevac) was used for N₂O analysis (mJz = 44). XRD results of Co-Mn-AI/TiO₂ catalysts confirmed presence of TiO₂ (anatas) and Co-Mn-Al spinellike oxides (not shown). The observed diffraction lines in Co-Mn-Al-carb and Co-Mn-Al-nitr catalysts were ascribed only to the spinel-like oxides. All samples exhibited a relatively low crystallinity with exception of Co-Mn-Al mixed oxide prepared from nitrates (Co-Mn-Al-nitr) which showed sharp and high diffraction peaks. The finding is in good agreement with the results describing their porous structure: Co-Mn-Al-nitr catalyst had much more smaller volume of micro- and mesopores, four times lower specific surface area and two limes higher mean mesopore radius (Table 1). Slight decrease in pore volume, specific surface area and mean pore radius were observed with increasing amount of Co-Mn-Al oxide in the supported catalysts. The temperature dependences of N₂O conversion are shown in Fig. 1. Pure TiO₂ was completely inactive at given experimental conditions. The increase of N₂O conversion with increasing amount of Co-Mn-Al oxide in Co-Mn-Al/TiO₂ catalysts was observed except the 25% Co-Mn-Al/TiO₂ sample. Conversion curve of N₂O obtained with the catalyst prepared by calcination of Co-Mn-Al LDH precursor (Co:Mn:Al molar ratio of 4:1:1) in our previous work [1] is also included in Fig. 1 (sample Co-Mn-Al-HT-ex). 155 NOE A 2011 Zakopane 4-7 September 2011 Table I. Structural and catalytic properties of Co-Mn-AI/Tt()₂ samples Sample ‘'’BIT Vmeso (m²g') (cm³g') r ²> V ³⁾ ' meso v micro (nm) (mm’g¹) 4, NA) reacted⁵¹ ⁶",c"’ (IO⁶ mol/m² of ⁽ⁿm⁾ catalyst) TiO2 200 0.54 - - 0 1 % Co-Mn-Al/TiO2 100 0.45 II.1 43 0.41 68.0 7% Co-Mn-Al/TiO2 95 0.42 11.4 40 0.40 5.3 14% Co-Mn-Al/TiO2 96 0.37 10.0 41 0.39 4.6 16% Co-Mn-Al/TiO2 91 0.32 9.5 39 0.39 15.0 25% Co-Mn-Al/TiO2 74 0.23 9.0 32 0.39 8.6 Co-Mn-Al- nitr 35 0.15 21.7 15 0.47 10.1 Co-Mn-Al- carb 134 0.78 12.4 58 0.36 8.4 Co-Mn-Al-HT-ex 93 0.48 12.2 ¹¹ Cumulative mesopore volume. BJH method;²’ Mean mesopore radius, BJH method;'¹ Cumulative micropore volume, Horvath Kawazoe method;⁴¹ Mean micropore radius, Horvath Kawazoe method; ⁵⁾ at 450 °C The Co-Mn-Al-HT-ex and Co-Mn-Al-carb catalysts were the best samples and showed the same behavior of N₂O conversion curve on reaction temperature. The Co-Mn-Al-nitr was the worst from the Co-Mn-Al mixed oxide samples mentioned above. Figure I. Temperature dependence of N₂O decomposition over Co-Mn-Al mixed oxide supported on TiO₂. Conditions: 0.1 mol% N₂O balanced in He, atmospheric pressure, GHSV = 601 g¹ h¹. From the presented results, it is evident that specific catalytic activity expressed as reacted moles of N₂O per 1 m² of catalyst surface is nearly the same with the exception of 1% Co-Mn-AI/TiO₂ catalyst, which was likely caused by big experimental error at low N₂O conversions (Table 1). Titania in all 156 NOEA2011 Zakopane 4-7 September 2011 Co-Mn-AI/TiO₂ catalysts acts only as a catalytic support and does not contribute to their catalytic activity. Different procedure used in preparation of the pure Co-Mn-Al mixed oxides had crucial influence on morphology of resulting materials and achieved N₂O conversions. However, their specific activities were the same within the experimental error. This work was supported by the Czech Science Foundation (project No. 106/09/1664) and EU project No. CZ. 1.05/2.1.00/03.0100 „ Institute of Environmental Technologies “. [ 1 ] L. Obalova, K. Pacullova, J. Balabanova, K. Jiratova, Z. BastI, M. Valaskova, Z. Lacny, F. Kovanda, Catal. Today 119(2007)233 NOEA2011 Zakopane 4-7 September 2011 PS 19 Photocatalytic decomposition of N2O on Ag-TiCh K. KOĆI¹, S. KREJCIKOVA², Z. LACNY¹,0. SOLCOVA², L. OBALOVA* ¹ VŚB - Technical University of Ostrava, Faculty of Metallurgy and Materials Engineering, 17. listopadu 15, 708 33 Ostrava, Czech Republic ² Institute of Chemical Process Fundamentals CAS v.v.i., Rozvojova 135, 165 02 Prague, Czech Republic Until recently, nitrous oxide (N₂O) had received little attention as an atmospheric pollutant. Its harmful impact on the environment is now well recognized. N₂O plays a significant role in the destruction of the ozone layer. N₂O is also a major greenhouse gas. Photocatalytic decomposition of N₂O is one of the candidate methods for its removal. N₂O can be reduced by the electrons generated by UV irradiation on semiconductor photocatalysts, evolving N₂ and O₂. Titanium dioxide (TiO₂) is well known as photocalalyst for wastewater treatment, hazardous waste control, air purification, and water disinfection. However, TiO₂ (anatase) exhibits a relatively high energy bandgap (3.2 eV) and can only be excited by high energy UV irradiation with a wavelength shorter than 387.5 nm. Efforts have been made to extend the light absorption range of TiO₂ from UV to visible light and to improve the photocatalytic activity of TiO₂ further by adding noble metals. For example, Ag can serve as successful dopant to TiO₂ for increasing yields of several types of photocatalytic reactions [1], evaluation of Ag-TiO₂ efficiency for N₂O photocatalytic decomposition is the aim of presented work. Silver-enriched TiO₂ powder was prepared by the sol-gel process controlled in the reverse micellar environment and characterized by X-ray diffraction (XRD), nitrogen adsorption measurement and UV-Vis HL The photocatalytic measurements of N₂O decomposition were carried out in a homemade apparatus al ambient temperature. A batch annular reactor was fill with 600 ppm N₂O/air mixture (volume 756 cm³, pressure 110 kPa) and illuminated by an 8 W Hg lamp with a peak light intensity at 254 nm (Ultra-Violet Products Inc., USA, 11SC-1) situated in the center of the quartz tube; the shell tube was made from stainless steel. The Ag-TiO₂ powder (0.215 g) was distributed evenly over the adhesive tape located in the bottom of reactor. GC/TCD was used for the analysis of N₂O. The N₂O concentration level was measured before switching of UV lamp and during the irradiation. The basic textural properties of prepared doped titania sample are summarised in Table 1 together with real Ag content. The sample possesses a relatively high surface area. XRD analysis confirmed the presence of the pure anatase crystallite structure. The absorption edge value was evaluated from UV-Vis measurement [ I ], shift to the visible light region was observed compared to pure anatase. Table 1. Basic characterisation of prepared photocatalyst sample Sample Ag content Sbet I"max Absorption edge (eV) (wt.%) (m2/g) (nm) Ag-TiO2 0.725 80 1.41 2.88 ¹ Maximum pore radius Figure 1 shows the time dependence of N₂O conversion over Ag-TiO₂. The gradual increase of N₂O conversion was observed with increasing reaction time, N₂O conversion was about 75 % after 24 hours. The kinetic data of N₂O photocatalytic decomposition can be described by 1st rate law (Fig. 2): r = kcN₍₎ . , £ = 0.0509 h 159 NOEA 2011 Zakopane 4-7 September 2011 Figure 2. Evaluation of kinetic constant (lsl rate law) for N₂O photocatalytic decomposition by integral method The following mechanism of N₂O photocatalytic decomposition is proposed: When illuminated by UV light with a sufficient photonic energy (hv) and an appropriate wavelength, photon-generated electrons (e~) and holes (h⁺) are created on the surface of the Ag-Ti()₂ catalysts (Eq. 1-2). Furthermore, the photoexcited electrons and holes in the lattice are separated and trapped by the appropriate sites of Ag-Ti()₂ to avoid recombination. At first, the electrons react with N₂() adsorbed on the catalyst surface producing N₂ and «O radicals (Eq. 3). These incipient •()' radicals react with holes to produce ()₂ (Eq. 4). 160 The pholocatalytic properties of the nanocrystalline Ag-TiO₂ catalyst were evaluated by pholocatalytic decomposition of N₂O. Reaction kinetics was well described by Is¹ rate law, which is in agreement with plausible reaction mechanism where N₂O chemisorption (Eq. 3) is the rate determining step. The decomposition of N₂O by photocatalysts was one of the most promising methods, since N₂O can be decomposed to innocuous substances by irradiating it with UV light at room temperature, i.e. at the conditions when N₂O thermal catalytic decomposition does not proceed. This work was supported by the Grant Agency of the Czech Republic 203/08/H032 and EU project No. CZ. 1.05/2.1.00/03.0069 ,,ENET“. [ 1 ] K. Koći et al, Appl. Catal. B 96 (2010) 239 NOEA201I Zakopane 4-7 September 2011 PS20 Effect of V concentration in niobium-rich V-O-Nb/anatase catalysts on their activity in ammonia assisted DENOX P. KORNELAK¹, A. BIAŁAS*, D. RASIŃSKA¹, J. CAMRA², W. ŁASOCHA¹ ,W. ZHANG³, D. SU³, A. WESEŁUCHA-BIRCZYŃSKA¹, M. NAJBAR¹* ¹ Faculty of Chemistry, Jagiellonian University, 3 Ingardena St., 30-060 Kraków, Poland, *mnajbar@chemia.uj.edu.pl ² Faculty of Materials Science and Ceramics, AGH University of Science and Technology, 30 Mickiewicza Av.., 30-059 Krakow, Poland ³ Department of Inorganic Chemistry Fritz-Haber-Institut der Max-Planck Geselleschaft, Faradayweg, 4-6, D-14195 Berlin, Germany Anatase supported vanadia-niobia catalysis are frequently proposed as alternative for anatase supported vanadia-tungsta commercial ones for NO reduction by ammonia. The effect of niobium on the catalyst activity is not well understood by now. According to Ziolek [1] the addition of niobium to vanadia-titania catalyst improves their activity as a result of increasing amount of the surface redox and acid sites. Tanabe [2] have shown that addition of Nb to V₂O5/TiO₂ catalysts distinctly improves their low temperature activity and stability in NO SCR by ammonia. That conclusion has been supported by earlier Japan patents [3-6]. Those patents has also revealed an increase of mechanical strength of the catalyst due to Nb addition. Wachs et al. [7] have investigated anatase supported vanadia and niobia catalysis by Raman spectroscopy. They have claimed the absence of crystalline Nb₂O₅ and occurrence of two-dimensional overlayers, retarding the loss in surface area of the titania support, either on the Nb₂Oj/TiO₂ or V₂O₅/Nb₂O₅/TiO₂ catalysts surfaces. Schneider et al. [8] have found surface reconstruction of vanadia-niobia catalysts obtained by sol-gel method during calcinations at 723K. They have revealed that reconstruction, resulting in the vanadia patches and three dimensional structures formation, caused increase of the catalyst activity in NO SCR by NH₃. It is known that vanadia forms solid solutions in niobia [9,10], Thus, it could be expected that vanadium sites in niobia overlayers also show some catalyst activity in NO SCR by ammonia. To follow up this expectation, two titania supported vanadia-niobia catalysts with high niobia predominance (4.5 wt. % Nb₂O₅) and different vanadia content (1.1 or 2.2 wt.% V₂O₅) were obtained. The surface physico-chemical properties and SCR activity of these catalysts were investigated to explain the dependence of the catalyst activity on a number and a degree of oxidation of vanadium atoms in the surface Nb-O-V species. The anatase-supported V-O-Nb catalyst with atomic V:Nb ratio equal to 1:2.8 (1.1 wt.% V₂O₅ - 4.5 wt. % Nb₂O5/TiO₂) was obtained by sol-gel method from titanium isopropoxide, vanadyl isopropoxide and niobium ethoxide. This catalyst was used for obtainment of another one with twice higher content of vanadium by the deposition of the oxy-hydroxy vanadium sols on its sol particles. The characterisation of both the catalysts was performed using XRD, HRTEM, XPS and Raman spectroscopy. The results obtained for catalyst with 1.1 wt% V₂O₅ show the presence of the epitaxial layers of Nbₗ₈V₄O₅₅ mixed oxide phase on anatase nanocrystallites surface. However, the results for catalyst with 2.2wt% V₂O₅ reveals the transformation of epitaxial layers of Nbl8V4O55 into V₂Nb₆O|₉ nanocrystallites during the second step of its synthesis. The deconvolution of the V 2p₃/₂ peaks in XP spectra allowed to find that vanadium in the surface nannolayers of both the catalyst is present mostly at low oxidation states (I and III). The results of the catalytic test show that niobia-rich catalysts are active in NO SCR by ammonia mainly due to NO decomposition on interstitial vanadium cations with low oxidation state. NO decomposition is the rate determining step of NO SCR by ammonia at relatively low temperature and the 163 NOEA20II Zakopane 4-7 September 2011 active oxygen is not involved in oxidation-induced surface V segregation. The surface vanadium segregation results in vanadia species formation. The segregation appeared in catalyst with I. I wt% V₂O₅ content above 300°C and in the second catalyst, with twice vanadia loading, above 350°C. Ammonia is oxidised on vanadia-like species by molecular oxygen. The comparison of the phase and chemical compositions of the catalysts with their NO SCR activity allows to think that the surface interstitial vanadium atoms with low oxidation states in the mixed V-O-Nb phases play the role of the active sites. The oxidation-induced surface segregation of the interstitial vanadium atoms, resulting in vanadia species formation, is postulated to be responsible for the ammonia oxidation. [1] M. Ziółek, Catal. Today 78 (2003) 47 [2] K. Tanabe, Catal. Today 8 (1990) 1 [3] H. Ulsunomiya, K. Soga, K. Shimazaki, Y. Milo and M. Aoki, S. Haseba, H. Miki and M. Masaki, Ger. Offen, 2634279 (1976) [4] H. Ulsunomiya, K. Shimazaki, K. Soga, Y. Milo andM. Aoki, Japan Patent Kokai, 52-151688 (1977) [5] E Kurosawa, Japan Patent Kokai, 54-52692 (1979) [6] S. Haseba, S. Ito, Y. Mito and T. Hirano, Japan Patent Kokai, 55-28718(1980) [7] E. Wachs, J.-M. Jehng and F. D. Hardcastle, Solid State Ionics. 32/33 (1989) 904 [8] M. Schneider, U. Scharf, A. Wokaun and A. Baiker, J. Catal. 150 (1994) 284 [9] R. H. H. Smith, K. Seshan, H. Leemreize, J. R. H. Ross, Catal. Today 16 (1993) 513 [10] Z. Zhao, X. Gao, I. E. Wachs, J. Phys. Chem. B 107 (2003) 6333 164 NOEA2011 Zakopane 4-7 September 2011 PS21 Alloying effect on NO direct decomposition over high surface area Rh/AhOa catalysts A. PIETRASZEK¹, P. Da COSTA², P. KORNELAK¹, B. AZAMBRE³, L. ZENBOURY³, M. NAJBAR¹ ¹ Department of Chemistry, Jagiellonian University, 3 Ingardena St., 30-060 Kraków, Poland ² Laboratoire de Reactivite de Surface, Universite P. et M. Curie, 4 Place Jussieu, 75252 Paris Cedex 05, France ³ Laboratoire de Chimie et Applications, Universite Paul Verlaine de Metz - IUT Chimie.rue Victor Demange 57500 Saint Avoid A removal of NO, (NO and NO₂) from oxygen-containing off-gases of stationary sources of emission such as power and heat plants, nitric acid factories, waste-incineratorsand stationary Diesel engines is the fundamental problem of environmental catalysis. Nitrogen oxides NO, in those off-gases contain above 90% of NO. Nitric oxideis formed from air by endothermic N₂ oxidation at temperatures above 1000°C. Thus, NOis thermodynamically unstable molecule, with the high, positive formation enthalpy, it could decompose to N₂ and O₂ at low temperatures (between 20 and 700“C). The direct NO decomposition seems to be the best way of NO removal from off gases because of practical, environmental as well as economical reasons. This process does not require reducer that allows to avoid secondary pollutants like mildly oxygenated hydrocarbons, CO, NH₃ or even cyanate and isocyanate. However, in the case of direct NO decomposition N₂Ocan be formed besides N₂ because of two possible paths of the process: 2NO -> N₂ + O₂ 2NO —> N₂O +‘/2 O₂. Oxide supported precious metal catalysts are known to be the most active in direct NO decomposition among the metal catalysts supported on metal oxides. The aim of this research was to investigate the NO decomposition in the oxygen presence over Rh/5-AI₂O₃ catalysts with different loadings (0.06, 0.12 and 0.18wt.%). The trial was undertaken to determine the active sites of this process. High surface area alumina was obtained with the sol-gel method. The solution of RhCl₃*3H₂O in water was next added to the alumina sol solution. The precursor of the 0.06wt.%Rh/Al₂0₃ catalyst was obtained by solution evaporation, calcination and reduction in a hydrogen. The 0.12wt.%Rh/AI₂O₃ catalyst was synthesised from 0.06wt.%Rh/AI₂0₃ oneby repeating the same procedure. The 0.18wt.%Rh/8Al₂O₃ catalyst was obtained in the same way from 0.12wt.%Rh/Al₂O₃ one. The catalysts were characterised by measurements of BET specific surface area TPD of CO and NO adsorbed as well as DRIFTS of the CO adsorbed. The BET specific surface areas was found to increase continuously with deposition of two first portion of 0.06wt.% Rh on the alumina support and to decrease with the addition of the third such portion. Unexpected increase of the specific surface area with addition of third portion suggests the distinct separation of the Al-Rh alloy nanocrystallites from the larger alumina ones. The DIRFT spectraof the adsorbed CO clearly show the presence of Al-Rh alloy with atomically dispersed rhodium and rhodium modified alumina of enhanced oxygen mobility on the catalyst surface. The NO direct decomposition in reaction mixture containing 200ppm NO, 1600ppm methane, 7% oxygen and helium was investigated under steady-state conditions in 200 - 400°C temperature range at GHSV=20000h '. The steady-state experiments were performed in a quartz flow reactor using 0.2g of the catalyst in the direction from 400 to 200°C, after pre-treating the catalysts in the reaction mixture at 500°C .The NO conversion and the selectivity to N₂ as a function of temperature are presented in Fig. 1. 165 NOEA 2011 Zakopane 4-7 September 2011 Fig. I. The NO conversion (a) and selectivity to N₂ (b) on the 0.06 Rh/ SALOj , 0.12 Rh/ <)A1₂Oj and 0.18 Rh/ dAl₂Oₜ catalysts a function of temperature (0.200g; 2(X)ppm NO, 1600ppm CH₄ and 7 %O₂; GHSV=20000h') The highest NO conversion and the highest selectivity towards N₂ observed on ().18wt.%Rh/8Al₂O₃ catalyst at temperature range 200 - 300"C can be ascribed to the direct NO decomposition over separated Al-Rh alloy nanocrystallites. The surface Rh atoms with enhanced electron density on the surface of the Al-Rh alloy nanocrystallites are discussed to be active sites in direct NO decomposition. The drop of the activity and selectivity above 300°C distinctly shows a deep surface reconstruction. To check stability of the surface structure of the ().18wt.%Rh/8AI₂O₃ catalyst during the effective direct decomposition process at 200°C, the long-term (60 h) experiment was performed on the catalyst pre-treated at 400°C in the mixture of 15()ppm NO and 7%()>/He. The NO conversion to nitrogen was found to stay at the same level during 60 h and to be closed to that achieved at 200°C in the steady-state experiment presented in the Fig. 1. 166 NOEA2011 Zakopane 4-7 September 2011 PS22 NO decomposition over Mo-V oxide bronzes P. KORNELAK¹, M. ŁABANOWSKA¹, W. MACYK¹, M. TOBA², I. NAZARCZUK¹, M. NAJBAR¹ ¹ Department of Chemistry, Jagiellonian University, 3 Ingardena St., 30-060 Kraków, Poland ¹ National Institute of Materials and Chemical Research, 1-1 Higashi, Tsukuba, Ibaraki 305, Japan A precursor of an anatase-supported V-O-Mo catalyst with V:Mo:Ti = 1:9:90 was prepared by sol-gel method from water solutions of (NH4)₆Mo70₂₄-4H₂0 and VO(NO₃)₂ as well as 6% TiO₂ sol solution. A precursor of an anatase-supported V-0 catalyst with V:Ti =1:9 was prepared by sol-gel method from water solutions of VO(NO₃) and 6% TiO₂ sol solution. A precursor of an anatase-supported Mo-0 catalyst with Mo:Ti =1:9 was prepared by sol-gel method from water solutions of (NH₄)₆Mo7O₂₄'4H₂O and 6% TiO₂ sol solution. To obtain the catalysts the precursors were calcinated at 773 K in air for 3 hours. The catalysts were characterized by measurement of a nitrogen adsorption, EPR spectra, , and DR UV-Vis spectra and DRFTIR spectra of NO adsorbed. The activity of the catalysts was measured in u-tube quartz flow reactor on line with GC/MS equipped with DB-1 capillary column. Figure 1. DRFTIR spectra ofV-O-Mo/TiO₂ (a), MoOx/TiO₂ (b) and V₂O/TiO₂ (c) catalysts activated in He at 723K and next subjected to interaction with NO at room temperature (200ppm NO/He, 60cm³/min) The specific BET surface areas of all the catalysts are similar and close to 110 m²/g. An EPR spectrum of V₂Os/TiO₂ catalyst registered at 77 K consists of three signals: two of them exhibit hyperfine structure characteristic for V(IV) species the third signal is a broad, structureless line. 167 NOEA 2011 Zakopane 4-7 September 2011 The parameters of the first signal are similar to those of crystalline vanadia. Two other signals are ascribed to V (IV) substituted forTi in anatase structure. An EPR spectrum of the MoO₃/TiO₂ catalyst registered 77 K reveals three signals from Mo(V) species and one from Ti (III). The first signal is ascribed to Mo(V) in surroundings of oxygen atoms more symmetrical than that in orthorhombic MoO₃. The next two signals arc similar to those reported for interstitial Mo(V) in TiO₂ . Ti(III)species are formed as a result of Mo(V) substitution for Ti(lV) in anatase structure. In a spectrum of the mixed V-O-Mo catalyst six superhyperfine lines with A = 1.6 are overlapped on the hyperfine lines of vanadia indicating the interaction of an unpaired electron localized on vanadium with nuclear magnetic moment I =5/2, of ⁹⁵,⁹⁷Mo nuclei. This fact confirms incorporation of molybdenum in vanadia. A new signal from V (IV) appears in room temperature spectrum. This signal increases slightly with a catalyst reduction and drastically with its reoxidation. Ils behavior strongly suggests that it comes from V-Mo oxide bronze containing interstitial vanadium ions in molybdena-like structure. Surface interstitial vanadium atoms occurs as a vanadyl species containing V(V) and exposing oxygen at the surface while bare vanadium ions at lower oxidation states arc present in subsurface layers and in the bulk of bronze nanocrystallites. The reduction may cause some additional filling of the surface interstitial positions with surface vanadyl species at the cost of the surface vanadia species. However, reoxidation is expected to cause the replacement of the interstitial V cations with oxidation degree lower than IV from the bulk to surface of bronze nano- crystallites were they adsorb oxygen forming vanadyl species. Results of DR UV-Vis measurements confirm presence of Ti(III) and Mo(V) species in the fresh, reduced and oxidized V-O-Mo catalyst. A lack of absorption characteristic for crystalline V₂O₅ reveals predominant formation of V-Mo oxide bronze containing vanadium at oxidation degrees lower than IV. The DRFTIR spectra of NO adsorbed on the surface of the activated catalysts are presented in Fig. 1. Peaks at 1813 and 1713 cm'¹ observed only in DRFTIR spectrum of the mixed V-O-Mo catalyst are commonly ascribed to symmetric and asymmetric vibration in dinilrosyl species. The results of the catalytic tests show that direct NO decomposition proceeds mostly as a results of the interaction between NO groups in dinilrosyl species formed on the surface of the V-O-Mo catalyst. Publication co-financed by the European Regional Development Fund under the Innovate Economy Operational Programme 2007-2013, POIG.01.01.02-12-112/09 project. 168 NOEA 2011 Zakopane 4-7 September 2011 PS23 Effect of surface potassium doping and NOX addition on catalytic activity of iron and cobalt spinels in soot combustion P. LEGUTKO¹, P. STELMACHOWSKI¹, A. KOTARBA¹, Z. SOJKA¹ ¹ Faculty of Chemistry, Jagiellonian University, 3 Ingardena St., 30-060 Krakow, Poland Environmental pollution is an actual problem of today’s metropolises. In this aspect particulate matter emitted from diesel engines is paid particular attention because of its carcinogenicity and mutagenicity. The best way of soot elimination from exhaust gases is application of DPF (Diesel Particulate Filler) technology. However, gradual accumulation of soot and resulting reduction of filter cross-section leads to decrease of the exhaust gases flow rate or even complete filter clogging. Therefore, to recover the DPF functionality, the filter has to be periodicaly regenerated. The most eficient way of soot elimination by combistion is the use of oxidation catalyst [1],[2], It has been reported that nitric oxide (NO), which is always present in diesel exhaust, can severely influence the soot combustion process. Such effect was found for several oxide catalytic materials e.g. Ba-CuOₓ-CeO₂ [3], La₂O₃, [4] and MnOₓ-CeO₂ [5], as well as for spinel type oxides, such as ZnAl₂O₄ [6], BaAI₂O₄ [7], Cuo95Koo5Fe₂04 [8]. The effect of alkali promotion to soot combustion oxide catalysts has been well established [9], In particular, the influence of alkali addition (Li, Na and K) to ZrO₂ [10] CaO-MgO [11] was tested in a detailed way. Nonetheless, despite the progress made the beneficial role of alkali is still not understood, mainly due to the lack of systematic studies on the well defined systems. In the present work, the effect of potassium addition on iron and cobalt spinels in different gas feed composition: oxygen (5% O₂/He), oxygen-NO (3.3% O₂ and 1.7% NO/He) and in nitrous oxide (5% N₂O/He) was investigated. Temperature Programmed Oxidation measurements of soot were conducted in a fixed bed microreactor consisting of a quartz tube with a sinter. Printex80 (Degussa) was used as the model soot. The soot-catalyst mixture (mass ratio 1:8) was prepared by grinding in agate mortar (tight contact). Gas flow was 60 ml/min and temperature range from RT to 900 °C (heating rate 10°C/min). The gas composition was monitored by QMS (RGA 200, SRS). All investigated spinels are active catalysts in the oxidation of soot, however they exhibit diverse behavior in the different conditions. In the presence of 5%O₂ alone the cobalt spinel CO3O4 shows belter activity than Fe₃O4 and unpromoted reference catalyst (Fig. I). The effect of potassium addition was rather weak and leads to increase in soot ignition temperature in each case. Addition of NO to the feed changes the trend by decreasing the ignition temperature for iron spinels, whereas for cobalt spinel the temperature increased. Interestingly, in the presence of NO, potassium doping lead to spectacular increase of activity of all investigated catalysts. In the presence of N₂O all catalysts showed substantially lower activity than in the presence of oxygen, despite that N₂O is readily decomposed into N₂ and surface oxygen species. Most probably it is caused by enhanced recombination of reactive adspecies, which hinders their involvement in soot oxidation. 169 NOEA2011 Zakopane 4-7 September 2011 Figure 1. Temperature of ignition of soot in different gas phase composition (O₂ and O₂+NO)for undoped and K-doped Fe₃O₄, Co₃O₄, (*) catalyst composition is subject to a patent application. The obtained results confirm that NO presence has beneficial effect on soot particles oxidation. This effect may be dramatically enhanced upon promoting with potassium, reaching, at suitable oxide surface, the soot ignition temperature, as low as 160°C. [1] B. A. A. L. van Setten, M. Makkee, J. A. Moulijn, Catalysis Reviews 43 (4) (2001), p. 489 [2] D. Fino, Science and Technology of Advanced Materials 8 (2007), p. 93 [3] F. Lin, X. Wu, D. Weng, Catalysis Today, Article in press (doi:10.1016/j.cattod.2011.03.002) [4] M. A. Peralta, M. A. Ulla, C. A. Querini, Applied Catalysis B: Environmental 101 (2010), p. 38 [5] X. Wu, F. Lin, H. Xu, D. Weng, Applied Catalysis B: Environmental 96 (2010), p. 101 [6] M. Zawadzki, W. Staszak, F. E. Lopez-Suarez, M. J. Ilian-Gomez, A. Bueno-Lopez, Applied Catalysis A: General 371 (2009), p. 92 [7] H. Lin, Y. Li, W. Shangguan, Z. Huang, Combustion and Flame 156 (2009), p. 2063 [8] H. Lin, Z. Huang, W. Shangguan, Chemical Engineering & Technology 31 (2008), p. 1433 [9] A. Aissat, S. Siffert, D. Courcot, R. Cousin, A. Aboukais, Comptes Rendus Chimie 13 (2010), p. 515 [10] D. Hleis, M. Labaki, H. Laversin, D. Courcot, A. Aboukais, Colloids and Surfaces A: Physicochemical and Engineering Aspects 330, p. 193 [11] R. Jimenez, X. Garcia, T. Lopez, A. L. Gordon, Fuel Processing Technology 89 (2008), p. 1160 170 NOEA2011 Zakopane 4-7 September 2011 PS24 TEM studies of transition metal oxide catalysts for NO decomposition L. LITYŃSKA-DOBRZYŃSKA¹, K. STAN¹ M. KOZICKI², M. NAJBAR² ¹ Institute of Metallurgy and Materials Science Polish Academy of Sciences, 30-059 Cracow, 25 Reymonta St., Poland ² Faculty of Chemistry, Jagiellonian University, 3 Ingardena St., 30-060 Kraków, Poland Some oxide phases formed on the surface of the tubes and foil sheets from acid-resistant steel(lH18N9T/1.4541) during thermo-programed oxidation where found to be active in direct decomposition of nitrogen oxides contained in off-gasses from stationary sources of emission [1]. The microstructure of these oxide phases, formed in different conditions, was examined by use analytical and high-resolution transmission electron microscopy (TEM) FEI Tecnai G² microscope at 200 kV equipped with EDAX energy dispersive X-ray (EDX) and high angle annular dark field detector (HAADF). In order to prepare TEM samples, the catalytic material was scraped from oxidised tubes or foils from acid-resistant steel and then the thin slices of it were placed on a carbon support copper grid. The separate thin crystals, transparent for electron beam were analyzed. The a-FejO₃ oxide and (NiCrFe)O₄ spinel were identified based on the electron diffractions and EDX microanalysis. In figure 1 the example of the TEM bright field image and electron diffraction pattern of a-Fe2O₃ crystal is presented. Figure 1. TEM bright field image of the a-Fe₂O₃ crystal and corresponding diffraction pattern (zone axis [ 110]); EDX spectrum and quantitative analysis result of the marked point 171 NOEA2011 Zakopane 4-7 September 2011 The oxide contains mainly Fe (about 40 at.%) and oxygen (about 58 at.%), although the small amount of Cr is also detected (Cu visible in the spectrum comes from the supporting grid). Because of very similar ionic radius of Fe³⁺ and Cr³* replacement of F³⁺ ions in tetrahedral positions by Cr³* ones in a-FejO₃ structure is well understood. Beside the iron oxide crystals, (NiCrFe)O₄ spinel ones were found in investigated samples (Fig. 2). Results of EDX microanalysis showed that spinel contains Fe (about 33at.%), Ni (15 at.%), O (45 at.%) and small amount of Cr and Mn. It reveals the presence of the ferrite with some Cr cations substituted for Fe³⁺ ones in tetrahedral position and Ni²⁺ and Mn²⁺ and possibly some amount of F³⁺ in octahedral ones. Figure 2. TEM bright field image of the (NiCrFe)O₄ crystal and corresponding diffraction pattern (zone axis [112]); EDX spectrum and quantitative analysis result obtained for the marked point Publication co-financed by the European Regional Development Fund under the Innovate Economy Operational Programme 2007-2013, POIG.Ol.01.02-12-112/09 project. [1] M. Najbar, J. Dutkiewicz, L. Lityńska-Dobrzyńska, A. Wesełucha-Birczyńska, I. Nazarczuk, S. Janiga, M. Kozicki, P. Komelak, A. Bielańska, W. Lasocha, „Simultaneous NO reduction and soot oxidation on transition metal oxide catalysts” in this Book of Abstract 172 NOEA2011 Zakopane 4-7 September 2011 PS25 DRIFT study of deNOₓ reaction over Cu/CeZrC>2 catalyst A. ŁAMACZ¹, A. KRZTOŃ¹, G. DJEGA-MARIADASSOU¹ ¹ Polish Academy of Sciences, Centre of Polymer and Carbon Materials, Zabrze, Poland According to the three function model on supported metal cation [1] deNO, reaction proceeds in three assisted catalytic cycles, which are not kinetically coupled, i.e. they do not have a common adsorbed species. The model concerns a reaction feed that composition is: NO + Oxygen in excess + Hydrocarbon (HC) as reductant, where HC depends on the application. The model makes an assumption of three following functions: Fl: NO+ 1602 = NO F2: HC + NO₂ = “oxygenates” + NO F3: 2NO + “oxygenates” = N₂ + CO₂ + H₂O The present work reports in situ DRIFT analyses during temperature programmed desorption of NO and deNOx reaction carried out on Cu/CeZrO₂ Its purpose is to identify the surface species formed during deNOx reaction on Cu(4)/CeZrO₂ and hereby confirm the particular functions (Fl, F2, F3) of the catalyst. The diffuse reflectance FT-IR measurements were carried out in situ in a temperature cell fitted with ZnSe windows. Temperature programmed desorption of nitric oxide (NO-TPD) was preceded by 40 minute adsorption of 250 ppm of NO on Cu(4)/CeZrO₂ at room temperature. The adsorption was carried out in the absence and in the presence of oxygen (250 ppm NO + 5 vol% O₂). NO-TPD experiments were carried out in flowing Ar. Spectra of catalyst surface during NO-TPD were collected at 50, 100, 200, 300 and 350°C, after 20 minutes of each isotherm. The reference spectra - of fresh Cu(4)/CeZrO₂ - were acquired in flowing Ar at 50,100,200, 300 and 350°C. Before all tests, the catalyst was heated ex situ at 550°C for 2 hours in order to eliminate from its surface nitrates and carbonates. Toluene adsorption on Cu(4)/CZ surface was studied by diffuse reflectance FT-IR during 80 minutes of catalyst exposure to 250 ppm of C₇H₈ in Ar, at 250°C. Spectra of catalyst surface during 80 minutes of exposure to 250 ppm NO + 250 ppm C₇H₈ + 5 vol % O₂/ Ar (deNOx reaction) were also collected at 250°C. The absorbance spectra were obtained by dividing single beam spectra of the catalysts in the proper gas mixture by the spectrum of fresh catalysts, collected at 250°C in flowing Ar. Figure 1 shows in situ DRIFS of Cu(4)/CeZrO₂ during toluene adsorption (black) and deNOx reaction (red), both carried out at 250°C. Il is observed, that the characteristic bands of toluene (3110-2700 cm'¹) adsorbed parallel to the catalyst surface (no out of plane C-H in 900-650 cm’¹ region) decrease significantly when the catalyst is exposed to the mixture of NO+C₇H₈+O₂/Ar. It implies that C₇H₈ is consumed in deNOx reaction. Moreover, the adsorption of toluene results in its oxidation by ceria-zirconia and CuO to CO₂, which adsorbs on the catalyst surface giving carbonates. According to Jacobs [2], the bands at 1504, 1360, 1066, 1014 cm’¹ can be assigned to different types of surface carbonates. The same author ascribes adsorptions at 2933, 2845, 2723, 1559, 1553, 1542, 1371, 1362 and 1248 cm’¹ to surface formates. Carbonates are undesirable surface species during deNOx reaction, because they may block the active sites of the catalyst. As observed on deNOx spectrum (red) the intensity of bands ascribed to surface carbonates and formats is much lower than on spectrum during toluene adsorption (black). Therefore, it is shown in Figure 1 that active sites for deNOx reaction on Cu(4)/CeZrO₂ do not suffer inhibition by carboxylate species. During adsorption on Cu(4)/CcZrO₂, toluene can also undergo mild oxidation to oxygenates (alcohols, aldehydes, ketones, carboxylic acids) that can yield dimerization. DRIFT spectrum collected during hydrocarbon adsorption shows the formations of benzaldehyde (2740 and 1653 cm’¹), phthalic anhydride (1829, 1793, 1159 and 1132 cm'¹) and benzoquinone (1653 cm’¹) [3] on catalyst surface. Toluene is activated on the catalyst surface to benzyl species, which react with the surface of Cu(4)/CeZrO₂ giving benzaldehyde, and 173 NOEA2011 Zakopane 4-7 September 2011 this can be successively oxidized to carboxylate species (e.g. formates). The oxygenates on catalyst surface are not observed in the presence of NO and O₂, what indicates that they are consumed by NO in the function 3 (F3) of deNOx process. This function takes place on copper cation. In the case deNOx reaction, the additional bands are observed: in the region 1600-1520 cm'¹ ² ³ ⁴ - corresponding to NO₃ species and at 1736 and 1694 cm’¹ - attributed to NO adsorbed on copper cation [4], Figure 1. Toluene adsorption (black) and deNOx reaction (red) (NO+Crfig+OfAr) on Cu(4)/CeZrO₂ In situ DRIFTS of deNOx reaction, as well as associated to it NO-TPD and toluene adsorption allow to investigate the mechanism of NO reduction by selected hydrocarbon and highlight the chemical modifications of catalyst surface. Presented above DRIFTS spectra obtained during catalyst exposure to the mixture of NO+O₂+C₇Hj proved the presence of surface nitrate species on Cu(4)/CeZrO₂, being the product of surface NO oxidation (first function of deNOx). Oxygenates that are produced in the second function of deNOx are utilized in the third function by NO, therefore their presence was not observed on Cu(4)/CeZrO₂ surface. ¹ ² ³ ⁴ [1] G. Djćga-Mariadassou, Catal. Today, 90 (2004) 27 [2] G. Jacobs, R.A. Keogh, B.H. Davis J. Cat 245 (2007) 326-337 [3] G. Busca, Catal. Today. 27 (1996) 457-496 [4] Z. Wu, Z. Sheng, Y. Liu, H. Wang, J. Mo J. Haz. Mat. 185(2011) 1053-1058 174 NOEA2011 Zakopane 4-7 September 2011 PS26 XRD study of oxide Ni-Fe-Cr catalysts for NO decomposition W. ŁASOCHA¹, A. RAFALSKA-ŁASOCHA¹,1. NAZARCZUK¹, M. NAJBAR¹ ¹ Faculty of Chemistry, Jagiellonian University, 3 Ingardena St., 30-060 Kraków, Poland Oxide layers, which showed high activity and selectivity to nitrogen in the direct decomposition of NO in the presence of large amounts of oxygen were produced on the surface of the foil strips and tubes made of acid-resistant austenitic steels. These oxide layers were created using several heating programs with the use of gas mixtures with different oxygen content. Among others methods, X-ray powder diffraction (XRPD) was used to determine the phase composition of the layers. The study was conducted either on powder samples obtained by scraping the surface oxide layer of oxidized tubes or directly on the pieces of the oxidized foils of stainless acid-resistant austenitic steels. Such studies show some technical difficulties due to: small size of the samples, thin layers of the tested product, metallic substrate - giving strong, often very little selective, diffraction pattern. In order to obtain optimal diffraction patterns, the following measurement setup was used: diffractometer X'Pert PRO MPD, 2-d detector PIXCEL, the Bragg-Brentano reflection geometry. Holder for transmission measurements with the sample sandwiched between layers of thin film, with very low X-ray scattering was used. Diffraction patterns were analyzed by HighScore program, using PDF-4 + (ICDD) database. For materials for which, the RIR parameters are deposited in PDF-4+ database, the program allows a semi-automated quantitative phase analysis. Such measuring setup will ensure good quality of the obtained results, and thus the certainty and reliability of carried out analysis. For example in the figure below we give the results of phase analysis of powder samples for the oxide phase which was scratched from the surface of the tube made of acid-resistant austenitic steel 1HI8N9T / 1.4541 subjected to 7 heating cycles consisting of thermo-programmed heating to a temperature of 840°C at a rate of 4 K/min and subsequent annealing at this temperature for 4 hours. Marked peak positions of a-Fe₂O₃ phase and spinel phase containing Cr, Fe and Ni indicate the presence of these phases in the oxide layer formed on the surface of the oxidized tube made of 1H18N9T /1.4541 steel. The presence of these phases has been confirmed by the results of electron diffraction (SAD) and Raman spectroscopy and indirectly by the results of Energy Dispersive X-ray Spectroscopy (EDS) and X-ray Photoeleclron Spectroscopy (XPS). 175 NOEA2011 Zakopane 4-7 September 2011 Figure 1. XRPD results of phase analysis of powder sample of the oxide catalyst. Publication co-financed by the European Regional Development Fund under the Innovate Economy Operational Programme 2007-2013, POIG.Ol.01.02-12-112/09 project. 176 NOEA2011 Zakopane 4-7 September 2011 PS27 Modified Synthetic Spinels as Catalysts for Low Temperature deNzO G. MANIAK¹, F. ZASADA¹, W. PISKORZ¹, P. STELMACHOWSKI¹, A. KOTARBA¹, Z. SOJKA¹ ¹ Jagiellonian University, Cracow, 30-060, Poland A large group of mixed valence metal oxides crystallizes in spinel structure with metal ions located in tetrahedral (Td) and octahedral sites (Oh). These compounds are represented by a general formula AB₂O₄, where, in the most cases, A and B are divalent and trivalent cations, respectively [1]. Spinels are widely investigated as potential catalysts in low temperature N₂O decomposition, which runs with the cationic redox mechanism triggered by a transfer of electron density. This induces a strong correlation between the electronic properties and catalyst activity observed elsewhere [2,3], One of the most active dcN₂O catalyst is based on cobalt spinel [2]which can be effectively promoted by alkali [2,4]. The aim of this work was to combine experimental methods and molecular modeling to explore the mechanistic role of the valence (+2, +3) and coordination (Td, Oh) of cobalt ions in the Co₃O₄ spinel. Selective structural doping with Mg, Al, Fe and surface doping with potassium were also investigated. juhl. The spinel samples were obtained by precipitation method from the corresponding nitrate precursors. K-doping (2 atoms-nm'²) was achieved by incipient wetness impregnation from K₂CO₃. The samples were characterized by XRD (X’pert), SEM (Hitachi), TEM (TECHNAI, FEI), BET (Quantasorb), UV-VIS(Shimadzu), XPS (Prevac). Electronic properties were evaluated by the work function measurements using a Kelvin probe (KP 6500, McAllister). The TPSR-QMS of deN₂O were performed. For all calculations, the DFT level of theory was chosen and the Vienna ab initio simulation package (VASP) [5] was used for the (100) plane. The deN₂O TPSR profiles for all samples are shown in Fig. 1. The results clearly show that complete substitution of cobalt in Td and Oh sites by Mg²⁺ and Al³⁺ ions, respectively, in Co₃O₄ caused decrease of catalytic activity, which is reflected in the modification in the obtained activation energies (from 63 kJ-mof¹ for Co₃O₄, 71 kJ-mof¹ for MgCo₂O₄, 117kJ-mor' for CoAl₂O₄ to 193 kJ-mof¹ for MgAl₂O₄). Further enhancement of the catalytic activity achieved by surface doping with potassium revealed that the most pronounced effect occurs again for Co³⁺ ions in Oₕ positions (Co₃O₄ and MgCo₂O₄) confirming definitely their role as the active sites for deN₂O reaction. The strong improvement of the surface reactivity observed as 50% conversion temperature lowering (AT5o% in Table I) correlates with decrease in the work function by potassium addition (A4>). Table /. Selected structural and kinetic parameters for spinel catalysts CO3O4 MgCo2O4 COA12O4 Unit cell period 8.04 8.08 8.05 F^fdOO) 1.37 1.57 1.39 K adsorption / kcal- mol'1 102.1 88.9 92.1 A7 5o% 1 °C 161 133 82 A*/eV 0.49 0.09 0.05 The calculated change in surface atomic Bader charge of the K ion upon adsorption is +0.66, 0.52 and 0.58 for Co₃O₄, MgCo₂O₄ and CoAI₂O₄, respectively, indicating a pronounce transfer of the electron density to the surface in each case. However, the corresponding variation of the partial charge of the octahedral ions (electron density transfer indicated by an arrows in Fig. 2), adjacent to the potassium differs 177 NOEA 2011 Zakopane 4-7 September 2011 for the investigated oxides. It was calculated as -0.09, -0.02 and -0.13 for Co₃O₄, CoA1₂O₄, and MgCo₂O₄, respectively. Most pronounced changes in partial charge were observed for Co⁰¹¹ presented in Co3O₄, and MgCo₂O₄. Al octahedral ions presented in CoA1₂O₄ are weakly affected by an electron transfer. The obtained results indicate that the prime deN₂O active sites can be identified with the octahedral Co³⁺ ions, whereas the tetrahedral Co²⁺ ions alone are much less active, however they play a role of beneficial modifiers for catalytic performance of octahedral Co³⁺. Figure 1. TPRS profiles forMgAl₂O₄, MgCo₂O₄, CoAl₂O₄ and for Co ₃O₄ catalysts Figure 2. Perspective view of potassium adsorbed on the (J00) plane of cobalt spinel. [1] S.-H. Wei, S. B. Zhang, Phys. Rev. B 63 (2001) 045112 [2] F. Zasada, P. Stelmachowski, G. Maniak, J.-F. Paul, A. Kotarba, Z. Sojka, Catal. Lett. 127 (2009) 126 [3] L. Obalovd, G. Maniak, K. Kardskovi, F. Kovanda, A. Kotarba, Catal. Commun. 12 (2011) 1055 [4] P. Stelmachowski, G. Maniak, A. Kotarba, Z. Sojka, Catal. Commun. 10 (2009) 1062 [5] J. J. Hafner, J. Comput. Chem. 29 (2008) 2046 178 NOEA20I1 Zakopane 4-7 September 2011 PS26 The use of DESONOX type catalysts to remove nitrogen oxides during coal combustion A. MARCEWICZ-KUBA¹ ¹ Zakład Chemii Środowiskowej, Wydział Chemii, Uniwersytet Marii Curie-Skłodowskiej, 20-031 Lublin Pi. M.C.Skłodowskiej 3 The aim of this study was to determine the effect of a DESONOX type catalyst to reduce emissions of harmful gases such as SO₂, CO₂ and NOx evolved during combustion of coal with :Bogdanka” mines. To coal, the catalyst was added at a ratio of 1:1000 and 1:500. Then weighed sample weighing about lg, on an analytical balance to the nearest 0.1 mg. Samples of coal and coal with the catalyst addition burned in a quartz, reactor at the temperature of 1273 K. Each sample of coal and coal with the catalyst at various concentrations was burned several times. The exhaust gases were analyzed by gas analyzer IMR 3000. The analyzer measures the concentration level of O₂, CO, CO₂, SO₂ and NOx. Data from the analyzer were transmitted „on line" to the computer. The degree of reduction in emissions of SO₂, CO₂, NOx in the flue gas are calculated on the basis of the average concentration of these gases compared with the base, pure coal. Addition of catalyst DESONOX type to coal in an amount from 0.1 to 0.2 wt. % causes significant reduction of SO₂ ,CO₂ and NOx in waste gases generated during combustion of coal samples. Reduction of sulfur dioxide is from 26 to 59 %, carbon dioxide from 27 to 37 % and nitrogen oxides from 25 to 40%. The DESONOX type catalyst changes the combustion process and increases calorie burning fuel by better burning, also reduces the amount of tar evolved during combustion of coal. 1. The DESONOX type catalyst concentration in coal in an amount from 0.1 to 0.2 wt. % reduces the concentration of SO₂, CO₂ and NOx in the flue gas. 2. With the increase in the amount of catalyst in the coal increases the degree of reduction of harmful gases evolved during combustion of coal samples. 3. Almost twice the effect of a decrease of sulfur dioxide, carbon and nitrogen oxides in the exhaust gas was observed at a ratio of 1:500 the DESONOX type catalyst to coal, that is 0.2 wt. % catalyst in the coal. 4. Coal with the addition of the DESONOX type catalyst bums more and the amount of more evolved tar is less, which means that the ratio of CO₂ to the combustion time of coal samples modified as follows: clean coal - 2.75, with the addition of a DESONOX typecatalyst as 1:1000 - 2.04 and for the ratio of 1:500 - 1.98. This means that the concentration of the tar in the gas phase decreased in the first case, declined by 26 % in the second case about 28%. 179 NOEA2011 Zakopane 4-7 September 2011 PS29 Multi-step TPSR/QMS technique to study kinetics of NOx SR with ammonia D. Me CLYMONT¹,.!. OCHOŃSKA²³, S. KOŁACZKOWSKI¹, J. LOJEWSKA³ ¹ Department of Chemical Engineering, University of Bath, Claverton Down, Bath BA2 7AY, UK ² Institute of Chemical Engineering of the Polish Academy of Sciences, 5 Bałtycka St., 44-100 Gliwice, Poland ³ Faculty of Chemistry, Jagiellonian University, 3 Ingardena St., 30-060 Krakow, Poland The context of the study is connected with the renewable sources of energy from biomass gasification (e.g. forestry residue, farming residue, municipal waste), to obtain biogas (H₂, CO, CO₂, N₂, HCs) in gas engines. Gas engines (turbines) producing electricity or hot water provide energy at a local level. A major challenge is to develop appropriate catalytic technology for the treatment of exhaust gases (from the engine), to meet the new European Waste Incineration Directive (WID) for this type of a process. The problem of the exhaust gases installation lies in their immense size, ammonia slip, thermal deactivation (hot spots) and catalyst based on nobel metals. The remedy can be the application of the so called structured reactors based on metallic short channel structures of enhanced mass and heat transport [ 1 ] that are able to considerably shorten the reactor length. The application of such structures is entirely dependent on the development of new, highly-active catalysts with an increased conversion adjusted to high transport properties and also the methods of catalyst layering on the metallic surface. In line with the requirements stated by the structured reactors and the NH₃-SCR process seem the copper-exchanged zeolites, which are known for their remarkable activity both in in the nitrogen oxides reduction and also in direct NO decomposition [3,4], This work focuses on the optimization of the Catlab system equipped with tubular reactor and QMS for kinetic studies of NOx selective reduction with ammonia in the presence of oxygen. The equipment enables the multislep TPSR reactions including reduction, oxidation and desorption which used in a sequence provide the information on the active centres for the process. In this study. A real challenge is a proper calibration of the QMS detector for this kind of purposes. For this study the Cu²⁺-Y zeolite was prepared by exchanging the steamed form of NH₄⁺-Y zeolite (LZY-82, Linde of Si/Ali™, = 4.5) by threefold ion exchange from aqueous solution of Cu(NO₃)₂ at 85°C.The sheets of kanthal steal were used as the catalyst carriers. As a reference the ZSM-5 zeolite was also tested. The catalyst was deposited on the surface of the precalcined (1000°C) and washcoated (A1₂O₃ or TiO₂) surface of the carriers by impregnation. Both forms of the zeolite catalyst: powder and deposited one were subjected to further analyses. According to the results the most abandoned reactive intermediates during the reaction is oxygen and ammonia and reaction proceed through Rideal-Eley mechanism on Cu* centres on zeolite cavities [ 1 ] A. Kołodziej, J. Lojewska, Mass transfer for woven and knitted wire gauze substrates: Experiments and modeling,Catal. Today 147S (2009) S120—S124 [2] P. Jodłowski, J. Ochońska, D. McClymont, B. Gil, T. Łojewski, A. Kołodziej, S. Kołaczkowski, J. Lojewska,Modelling of structured reactor based on wire gauzes and zeolite catalyst for ammonia reduction of NOx from biogas turbine, submitted to Catalysis Today ((NOEQ 2011) [3] P. Pietrzyk, B. Gil, Z. Sojka, Catal. Today 126 (2007) 103-111 [4] K. Sun, H. Xia, Z. Feng, R. San ten, E. Hensen, C. Li, J. Catal. 254 (2008) 383 181 NOEA2011 Zakopane 4-7 September 2011 PS30 N₂O formation during lean NOX reduction by hydrocarbons over a conventional DOC D. MRAĆEK¹, Ś. BARTOVA¹, F. PLAT¹, P. KOCI¹*, M. MAREK¹ ¹ Department of Chemical Engineering, Institute of Chemical Technology, Prague, Technicka 5, CZ 166 28 Praha, Czech Republic Corresponding author, e-mail: petr.koci@vscht.cz, http://www.vscht.cz/monolith Diesel oxidation catalyst (DOC) is utilized for the oxidation of CO and unbumed hydrocarbons (HC) in the diesel exhaust gas. The DOC is also able to reduce a part of nitrogen oxides (NOX) by so-called lean NOx reduction by hydrocarbons (HC-SCR) under excess of oxygen. However, a major by-product of this lean NOX reduction is N₂O - a strong green-house gas (GWP=320). Even if the emitted N₂O concentrations are low and the contribution of automobiles to global N₂O emissions is not major, it is expected that it will be included in future automotive emission regulations. Experiments were carried out with an industrial DOC in nearly isothermal lab mini-reactor containing three identical monolith samples in series. The inlet gas mixture was prepared online from the individual synthetic gases (CO, C₃H₆, O₂, NO, NO₂, CO₂, H₂O and N₂) [1], The experimental series consisted of the ligh-off experiments performed within temperature range 80-400°C (2°C/min). The inlet gas composition was systematically varied to evaluate the effects of NOX, C₃H₆, O₂ and CO concentration as well as the inlet NO₂/NOX ratio. The space velocity was 35 000 h'¹. A set of experiments with different inlet concentrations of individual components was performed and the results were obtained by comparing them. The light-off curves of reducing agents (CO and CjHj) were analyzed to evaluate model reaction kinetic parameters (cf. Fig. 1). These effects were observed either in presence of both components, or separately without influence of their interaction. The oxidation of CO ignites below 150 °C, while C₃H₆ is oxidized more slowly and exhibits light-off at somewhat higher temperature (150-200 °C). A typical evolution of the outlet NOX, NO₂ and N₂O concentrations during a slow temperature ramp is shown in Fig. 2. At low temperatures, the NO oxidation to NO₂ is inhibited by the presence of CO and C₃H₆. This inhibition diminishes above the CO and C₃H₆ oxidation light-off and the production of NO₂ increases. It can be seen that a part of NOX is reduced during the C₃H₆ light-off. After reaching the maximum level of NOX reduction (200 °C), the outlet concentration of nitrogen oxides begin to increase again and the NOX reduction conversion gradually decreases to zero. This is caused by a sharply increasing rale of C₃H₆+O₂ reaction that competes with the NOX reduction. The NOX reduction curve correlates well with the N₂O formation curve, indicating that N₂O is a major product of this lean NOX reduction by C₃H₆ over noble metal sites. The situation with a higher propene concentration is displayed in Fig. 3. It can be seen that higher C₃H₆ concentration leads to a higher NOX conversion. The selectivity towards N₂O decreases only slightly and remains still very high. Fig. 4 shows a case, when CO is present in a higher concentration. CO exhibits a strong inhibition effect on the light-off. 183 NOEA2011 Zakopane 4-7 September 2011 184 NOEA2011 Zakopane 4-7 September 2011 Figure 4. Dependence of outlet concentrations of NO, NO₂ and N₂O on temperature, inlet: C₃H₆ = 200 ppm, CO = 1500 ppm The experimental results show that the lean NO, reduction takes place around the light-off of reducing agents, however only when C₃H« is present (pure CO exhibits negligible lean NO, reduction activity). At low C₃H« concentrations, almost all NO, reduction leads to N₂O. Increase of the inlet C₃H₆ concentration improves NO, conversion and slightly also the selectivity towards desired product N₂. Decreasing inlet 62 concentration in the inlet gas also enhances NO, reduction, but to a smaller extent NO, adsorption was observed in the same temperature range as the NO, reduction, with a significant competition between NO, and CO adsorption (CO disables the NO, adsorption below the light-off temperature). 185 NOEA 2011 Zakopane 4-7 September 2011 [ 1 ] http://www.vscht.cz/monolith [2] D. Kryl, P. Koći, M. Kubfćek, M. T. Marek, T. Maunula, M. Ind. Eng. Chem Res. 44 (2005) 9524 Hiirkónen, NOEA 2011 Zakopane 4-7 September 2011 PS31 Effect of O2, SO2 and H₂O on NO decomposition over Ni-Cr-Fe oxide catalysts J. DUTKIEWICZ¹, S. .JANIGA¹,1. NAZARCZUK¹, M. KOZICKI¹, P. KORNELAK¹, M. NAJBAR* Faculty of Chemistry, Jagiellonian University, 3 Ingardena St., 30-060 Kraków, Poland An anatase-supported V-O-W catalysts are commonly used to abate NOX emission from stationary sources by their reduction with ammonia. However, ammonia is corrosive, relatively expensive, and poisoning. NO is the main component of NOX in off-gases of stationary sources of emission. It is formed in endothermic N₂ oxidation and shows high thermodynamic instability. Thus, a direct decomposition of NO could be the best method of NO removal. Recently, Reichert et al. 11-2] performed an interesting investigation of the reaction of NOX and soot on Fe₂O₃ catalyst in excess of O₂. They have postulated, the direct NO decomposition on carbon activated by oxygen species formed on Fe₂O₃. Pirogova et al. [3] investigated activity of chromites with a spinel structure in NO decomposition in the reducer presence. Figure I. Temperature dependence of the CN₍> and the SN₂ in the direct NO decomposition on a powdered Ni-Cr-Fe oxide catalyst scraped off a surface of a acid-resistant IH18N9T/4541 steel tube, where it was formed in the course of a few thermal treatments composed of the heating to 84ff’C and next annealing at this temperature for 4 h; catalyst-0.200g, reaction gas-2()()ppmNO/He; GHSV= 7000h'. We have investigated the activity of the Ni-Cr-Fe oxide catalysts in the direct NO decomposition (200ppm-2%NO): i/ in the absence of any other reactants, ii/ in the presence of 5-7.4% of O₂, iii/ in the presence of 7.4% of O₂ and 200-1600ppm SO₂ iv/ in the presence of 7.4% of O₂, 200ppm SO₂ and 20-40ppm H₂O. 187 NOEA2011 Zakopane 4-7 September 2011 That catalyst was formed on surfaces of the austenitic acid-resistant supports (tubes, sheets of foils and monoliths) as a result of their thermo-programmed heating and next annealing in oxygen-conlaining atmosphere. Catalytic tests were performed either in a tubular quartz reactor on line with H-P 5890 GC equipped with Molsieve 5A column and TC detector (1 and 2%NO/He) or in an u-tube flow reactor (160-1000ppm NO/He) on line with Agilent Technologies GC-MS equipped with a capillary DB-1 column. In Fig. 1 temperature dependences of the NO conversion (CN₀) and selectivity to N₂ (SN₂) in the direct NO decomposition (200ppmNO/He, GHSV= 7000h ') on a powdered Ni-Cr-Fe oxide catalyst (0.200g), are presented. The catalyst was obtained on the surface of the acid-resistant 1H18N9T/1.4541 steel tube (wall thickness ca. I mm) in the course of thermal treatment composed of the heating to 840°C in air and next annealing at this temperature for 4 h. It was placed on a quartz crust in the u-tube flow rector and was activated at 600°C in helium for Ih prior the activity test. The activity and selectivity to N₂ were determined from the results of the periodical analyses of the effluent gas. In the whole temperature range the SN₂ is close to 100%, whereas CN₀ achieves 100% at 400°C. The results (not shown here) of the analogous experiment performed with the use of reaction gas composed of 200ppm NO, 7.4% O₂ and helium balance show an increase of the NO conversion to nearly 100% in a 150-350°C temperature range and a slight decrease in the selectivity to N₂ at the highest temperatures. However, the results (not presented here) of the analogous experiment with the use of the reaction gas composed of 200ppm NO, 7.4% O₂ and 200ppm SO₂ and helium balance reveal SO₂ addition does not cause distinct changes in CN₀ and leads to some increase of the SN₂ at the highest temperatures Publication co-financed by the European Regional Development Fund under the Innovate Economy Operational Programme 2007-2013, POIG.01.01.02-12-112/09 project. [ 1 ] D. Reichert, H. Bockhom, S. Kureti, Appl. Catal. B: Environ. 80 (2008) 248 [2] D. Reichert, T. Finke, N. Atanassova, H. Bockhom, S. Kureti, Appl. Catal. B: Environ. 84 (2008) 803 [3] G. N. Pirogova, N. M. Panich, R. I. Korosteleva, Yu. V. Voronin and N. N. Popova, Russian Chemical Bulletin, International Edition, 50 (2001) 2377 188 NOEA2011 Zakopane 4-7 September 2011 PS32 NOX uptake and storage properties of BaOₓ/Pt(lll) model catalyst: influence of Ba coverage, surface morphology and stoichiometry E. ÓZENSOY¹*, E. VOVK¹, E. EMMEZ¹ ¹ Department of Chemistry, Bilkent University, Ankara 06800, Turkey, Corresponding author: ozensoy@fen.bilkent.edu.tr Atomically ordered, BaO ultrathin films were synthesized on a planar Pt(l 11) single crystal to obtain a reverse model catalyst for NO, Storage Reduction catalytic processes. The structure of the BaO nano-domains and their relevance to NOX catalytic chemistry was investigated under UHV conditions using a combination of XPS, LEED and TPD techniques. NOX storage reduction or Lean NOX technology, which is commonly referred as NSR or LNT, is a promising after treatment technology for lean-bum engines. However there is still very limited knowledge regarding the catalytic processes that occur during the NSR systems at the molecular scale. [1-4] In order to address some of the important fundamental surface science issues relevant to the molecular understanding of the NOX storage process on the NSR catalysts, various BaOₓ/Pt(ll I) reverse model catalyst were synthesized and their interactions with NO₂(g) were investigated as function of the surface coverage, morphology and stoichiometry of the BaOₓ overlayer on the Pt(lll) single crystal substrate. Experiments were performed in a custom-design multi-technique ultra high vacuum (UHV) surface analysis chamber which is equipped with a X-ray photoelectron spectrometer (XPS),a quadruple mass spectrometer (QMS) for temperature programmed desorption (TPD) analysis, reverse-view low energy electron diffraction (LEED) optics, metal evaporators for thin-film deposition and high-precision gas dozers for adsorption studies. The typical base pressure of the UHV system was 2 x IO¹⁰ Torr Pt (111) single crystal substrate (Mateck GmbH) was mounted on the sample holder using Ta wires. Temperature of the sample was measured using a K-type thermocouple directly spot-welded on the Pt (111) crystal. The sample temperature can be varied within 100 K - 1100 K. Before the film growth, Pt (111) surface was cleaned by successive cycles of Ar⁺ ion sputtering and annealing in vacuum al 1073 K. BaOₓ films were grown using two different synthetic protocols which included evaporation of Ba from a BaAl(s) evaporation source followed by two different oxidation recipes. BaO/Pt( 111) (LEED) and decreasing NOX desorption maxima with decreasing Ba coverage after NO₂ adsorption on BaO/Pt( 111) (TPD). BaOₓ/Pl(lll) inverse model catalysts were prepared by either: i) evaporation of metallic Ba on a thick multi-layer of solid NO₂ on Pt (111) at 100 K followed by annealing in vacuum at 1078 K or ii) evaporation of metallic Ba on a thick multi-layer of solid NO₂ on Pt (111) at 100 K followed by oxidation in 1 x 1 O'⁷ Torr of O₂(g) at 1078 K. These two preparation procedures were repeated for various Ba surface coverages ranging from sub-monolayer BaOₓ overlayers to multi-layer (thick) BaO films. 189 NOEA2011 Zakopane 4-7 September 2011 Figure 1. NO₂ and NO₃ formation on (thick) BaO/Pt(lll) (XPS), crystal structure of different ordered overlayers for (thin) Various atomically ordered BaO„/Pt(lll) overlayers were detected in the LEED experiments for low Ba surface coverages while thick films led to amorphous disordered overlayers. Our XPS experiments revealed indications for the presence of BaO₂ for the model catalysts which were prepared by oxidation in the O₂(g) environment (procedure (if) while model catalysts prepared with vacuum annealing (procedure (ii)) resulted in BaOₓ (x < 1) stoichiometry. These two different types of overlayer stoichiometries also seem to have different surface morphologies for multi-layer (thick) Ba overlayers. This argument is supported by the TPD experiments, which showed the evolution of N₂(g) species after NO₂(g) exposure on (thick) BaO₂/Pt(l 11) surface implying the presence of exposed (uncovered) Pt sites which catalyze the activation of the N-0 linkages and formation of atomic N(ads) species which recombinatively desorb as N₂(g). On the other hand, (thick) BaO/Pt( 111) surfaces do not reveal a well-defined N₂(g) desorption signal due to the complete wetting of the Pt( 111) substrate with the BaO overlayer. Furthermore, influence of the Pt sites on the N-0 bond activation becomes even more evident for sub-monolayer BaO or BaO₂ overlayers on Pt(lll). As the surface coverage of Ba decreases, number of exposed Pt sites increases and these exposed Pt sites function as active reduction centers for the surface NO, species (which are in the form of nitrites and nitrates based on our XPS results) and efficiently facilitate decomposition of the adsorbed NOX species at lower temperatures [1] E. Ozensoy, J. Szanyi, C. H. F. Peden, J. Catal. 243 (2006) 149 [2] E. Ozensoy, J. Szanyi, C. H. F. Peden, J. Phys. Chem. B 110 (2006) 8025 [3] S. M. Andonova, G. S. Senturk, E. Ozensoy, J. Phys. Chem. C 114 (2010) 17003 [4] E. Vovk, E. Emmez, E. Ozensoy in preparation 190 NOEA20II Zakopane 4-7 September 2011 PS33 Selective Catalytic Reduction of NOX by C2H5OH over Ag/AhOa/cordierite N. POPOVYCH¹, P. KIRIENKO¹, S. SOLOVIEV¹ ¹ L. V.Pisarzhevsky Institute of Physical Chemistry of the NAS of Ukraine, 31 Prosp. Nauky, 03028 Kyiv, Ukraine, nataliepopovich@mail.ru The abatement of nitrogen oxides (NOX) emitted by mobile and stationary sources requires effective and durable SCR catalytic system that works in oxygen-rich environments. Among the various catalysts proposed for SCR with hydrocarbon or oxygenated organic reductants an alumina-supported silver was found to be the most active and potential catalytic system and has received considerable attention [1], The advantage of oxygenated compounds over hydrocarbons is their higher reactivity; moreover some oxygenated compounds (e.g. ethanol) are environmentally relatively benign and can be used as components of vehicle fuel. Structured catalysts are widely used for atmospheric emissions purification in practice but there are no research data about supported Ag/Al₂O₃ in literature. Thus study and design of structured catalysts for SCR NOX are an important challenge. Ceramic block matrices with a honeycomb structure made from synthetic cordierite (2Al₂O₃-2MgO-5SiO₂) were used as a catalyst support. The catalyst surface was formed by coating with y-Al₂O₃ (confirmed by XRD) from aqueous solution of KOH+aluminium swarf and by incipient wetness impregnation with an AgNO₃ aqueous solution. Then samples were dried in the air and calcined at 750°C. The silver and alumina loadings on the cordierite are reported in wt. %. The catalytic activity was characterized by the NO conversion (chemiluminescent detector) in the reaction mixture: 500ppm NO + 0.2%C₂H₅OH + 5%O₂ in He (GHSV = 20 000 h¹). The specific surface area was obtained by the thermal desorption of nitrogen (for samples after SCR). UV-Vis diffuse reflectance spectra (DRS) were recorded under ambient conditions on a Specord M40 with a standard diffuse reflectance unit (for samples after SCR). The spectra reported here were obtained by subtraction of the support spectrum to that of the Ag/Al₂O₃ supported samples. The catalytic results for samples with different content of Ag (Tab.l) show that there is almost complete conversion of NO for 0,1-0,5% Ag. It is clear from our results that not only silver content in the sample effects on the activity of structured silver-alumina catalysts, but also content of alumina. One can see that both over a composition 0.3%Ag/48%Al₂O₃/cordierite and over a 0.5%Ag/48%Al₂O₃/cordierite complete conversion of NO is achieved in the temperature range 300-450 °C but NO conversion over a 0.3%Ag/27%Al₂O₃/cordicrile is 95% al 340-360 °C and over a 0.5%Ag/27%Al₂O₃/cordierite is 80% at 300-330 °C. Complete conversion of NO over the catalyst 0.1%Ag/27%Al₂O₃/cordierite is observed for temperatures as high as 390-410 °C whereas for the sample 0.1%Ag/48%Al₂O₃/cordierite this range is much wider (380-440 °C) even in comparison with sample which contains three times more silver but only 27% y-AI₂O₃. Over the samples contained only alumina (N»2,7) temperature of 50% NO conversion for 48%Al₂O₃/cordierite on 70 °C lower than for supported 27%/Al₂O₃. It is worth noting that the deposition of silver up to 0,5% does not lead to a decrease in specific surface and in some cases (catalysts 3, 8 and 9) even increases specific surface of supported catalysts apparently due to highly dispersed distribution of silver on alumina surface. Thus, as clear from data in Tab.l, the most active structured silver-alumina catalysts are that with higher specific surface area (in terms of the same content of y-Al₂O₃ in the catalyst), and aren’t that with higher silver content. Probably the introduction of more than 0.5% of silver leads to its encapsulation in the depths of the alumina matrix. 191 NOEA 2011 Zakopane 4-7 September 2011 Tab. I. Catalytic activity and specific surface of cordierite-supported catalysts N» Catalysts NO Conversion, % /At, °C S. m2/g 1 l%Ag 0 1.5 2 27%A12O3 -50/450-500 24 3 0.1%Ag/27%Al2O3 -98/390-410 26 4 0.3%Ag/27%AI2O3 -95/340-360 22 5 0.5%Ag/27%Al2O3 -80/300-330 20 6 l%Ag/27%Al2O3 -35/290-340 22 7 48%A12O3 -50/380-500 38 8 0.1 %Ag/48%Al2O3 -100/380-440 44 9 ().3%Ag/48%Al2O3 -100/320-440 41 10 ().5%Ag/48%Al2O3 -100/320-440 38 11 1 %Ag/48%Al2O3 -100/300-330 38 12 1.5%Ag/48%Al2O3 -75/295-365 37 13 2%Ag/48%Al2O3 -70/270-290 37 Results of UV-VIS DRS show (Fig. I) that the greater part of silver is ions of Ag⁺ (the peaks at 225 and 260 nm) [2,3]. The peak near 450 nm could be assigned to metallic silver particles. Al high silver loading in the catalysts the peak near 450 nm is higher therefore the quantity of silver nanoparticles which are responsible for the total oxidation of the ethanol by oxygen is greater |4|. The increased content of alumina contributes to increase of silver dispersion on alumina surface and prevents its agglomeration in the process of catalyst preparation and at reaction conditions. Figure I. Diffuse reflectance UV-VIS spectra of samples (numbers of curves are identical to numbers in Table) 11] S. Kameoka, Y.Ukisu. T.Miyadera, Phys Chem Chem Phys. 2 (2000) 367 [2] N. Bogdanchikova, F.C. Meunier, M. Avalos-Borj, et al.. Appl. Catal., B: Environ 36 (2002) 287 [3] A. Musi, P. Massiani, I). Brouri, et al., Catal Lett 128 (2009) 25 [4] M.C.Kung, H.H.Kung, Top. Catal. 10 (2000) 21 192 NOEA20I1 Zakopane 4-7 September 2011 PS34 Study of the interaction of NOX and NH3 with the surface of copper and nickel catalysts supported on ceria-zirconia by FT-IR spectroscopy M. RADLIK¹³ A. ŁAMACZ¹, A. KRZTOŃ¹, W. TUREK² ¹ Polish Academy of Sciences, Centre of Polymer and Carbon Materials, Zabrze, Poland ¹ Silesian University of Technology, Department of Physical Chemistry and Technology of Polymers, Gliwice, Poland Nitrogen oxides (NO, NO₂ and N₂O) emitted from stationary boilers and mobile engines contribute to a lot of environmental problems. They are major source of acid rain, photochemical smog, ozone depletion and greenhouse effects [1,21. Several methods have been proposed for NOX removal [3]. One of the most promising and effective is Selective Catalytic Reduction SCR. This technology depends on both catalysts and reductant agent. Typical reductant agent are hydrocarbons, ammonia or urea. Among them ammonia is known to be very selective towards N₂ and provides high efficiencies [4]. Various catalysts have been investigated for NH₃-SCR deNOₓ, such as transition metal oxides, zeolite-based catalyst and noble metal catalysts [5]. Catalysts should be stable and active in the interaction with gas phase (containing NOX and NH₃). It can be observed by FT-IR spectroscopy in temperature DRIFT cell. This technique give information about the catalyst surface during adsorption NOX or/and NH₃ from gases phase and determining the structure of adsorbed species.. The aim of this work is to show structure of adsorbed species on the surface catalysts during deNOx experiments using, temperature DRIFT cell. The copper and nickel catalysts supported on ceria-zirconia, obtained by wet chemical impregnation with different amount of metal were studied during the interaction with gas phase, containing NOX and/or ammonia. We observed nitrate ions and different groups, like NHf, NH₂ for adsorbed NOX and NH₃ species respectively, similar to others work [6, 7], Among it we observed interaction NOX and ammonia with catalysts surface, allows to exclude no active catalysts and explains some details of mechanism of the ammonia in selective catalytic reduction. [ 1 ] Zhichun Si, Duan Weng, Xiaodong Wu, Jia Li, Guo Li Journal of Catalysis 27,43-51,2010 [2] Hideharu Iwakuni, Yusuke Shinmyou, Hiroshi Yano, Hiroshige Matsumoto, Tatsumi Ishihara Applied Catalysis B: Environmental 74, 299-306, 2007 [3] Zhiming Liu and Seong Ihl Woo Catalysis Reviews, 48,43-89,2006 [4] A. Boyanoa, MJ. Lazaroa, C. Cristiani, F.J. Maldonado-Hodarc, P. Forzatti, R. Molinera Chemical Engineering Journal 149, 173-182,2009 [5] Zhiming Liu and Seong Ihl Woo Catalysis Reviews, 48,43-89,2006 [6] Małgorzata Adamowska, Se'bastion Muller, Patrick Da Costa, Andrzej Krzton, Philippe Burg, Applied Catalysis B: Environmental 74,278-289, 2007 [7] Maria Casapu, Oliver Krocher, Max Mehring, Maarten Nachtegaal, Camelia Borca, Messaoud Harfouche, and Daniel Grolimund, J. Phys. Chem. C 114,9791-9801,2010 193 NOEA20I1 Zakopane 4-7 September 2011 PS35 Catalytic reduction of NO by CO over FeₓSiBEA catalysts I. HNAT¹,1. KOCEMBA¹’, J. RYNKOWSKI¹, S. DŹWIGAJ²* ¹ Institute of Ecological Chemistry, Technical University of Lodz, Poland ² Laboratoire de Reactivite de Surface,UPMC, CNRS, UMR 7197, 3 rue Galilee, 94200 Ivry-sur-Seine, France ^Corresponding authors: ireneusz.kocemba@p.lodz.pl, stanislaw.dzwigaj@upmc.fr Il is well known that iron loaded zeolites are active catalysts of selective catalytic reduction (SCR) of NO by hydrocarbons or ammonia [1,2]. Recently [3,4], we have reported that introduction of iron ions into the zeolite framework by two-step postsynthesis method allows to obtain a material with very good catalytic properties in SCR of NO by ethanol. It has been shown that catalytic activity of FeₓSiBEA zeolites strongly depends on the nature and state of iron introduced into the zeolite structure. In the present work this poslsynthesis method is used to obtain FeₓSiBEA catalysts (x = 0.6, 1.0, 2.0, 4.0 and 10 Fe wt %) with mainly iron present as isolated tetrahedral or octahedral Fe(III) species. The aim of this study is to investigate the influence of nature of iron on catalytic properties of FeₓSiBEA zeolites in SCR of NO by CO. This process, leading to the removal of two toxic reactants, is environmentally very important reaction. 2CO + 2 NO = 2CO₂ + N₂ (I) The aim of this work is investigation of the catalytic activity of FeSiBEA in the NO reduction with CO FeₓSiBEA catalysts (x = 0.3 - 10 Fe wt.%) were prepared by the two-step postsynthesis method described earlier [5]. As prepared FeₓSiBEA catalysts were calcined in air at 500 ° C for 3 h and reduced by CO for 0.5 h at 700 ⁰ C. The catalysts were characterized by different physicochemical methods: XRD, SEM, diffuse reflectance (DR) UV-VIS and TPR-CO. The catalytic tests were carried out using Temperature Programmed Surface Reaction method (TPSR) in a fixed-bed reactor (mass of the catalyst - 200 mg), in the temperature range 25 - 500 °C, with a linear increase in temperature (10°C /min). Gas mixture: 1 vol.% CO + I vol.% NO + He (balance) and total GHSV 4800 h'¹ was used. The changes in CO and N₂ concentration in the outlet of gas mixture were analyzed by Fuji IR Gas Analyzer and GC chromatography using a 5A molecular sieves column and TCD detector. The CO conversion and selectivity to N₂ were calculated by the following equations: CO conversion = ([CO],„ - [CO]„„,) / [CO]ⱼₙ * 100% (2) Selectivity to N₂ = [N₂ ]₍Mₜ / [N₂ ],/, * 100% (3) where [N₂],fₜ is theoretical concentration of N₂ according to reaction (1) calculated from equation: [N₂],„ ='/2([CO],„- [CO]ₒᵤ₁) (4) Table 1 shows the temperature of 50% conversion (T50) of CO and selectivity toward N₂ for FeₓSiBEA containing different Fe content. The CO conversion is relatively low, reaching only ca. 80% at 500 °C for the best catalysts. The different catalytic properties of FeₓSiBEA may be due to the different nature of iron species. Figure 1 shows CO conversion and the TPR-CO profile of Fei ₀ SiBEA sample. A striking feature is the similarity of CO conversion and TPR-CO profiles. It can indicate the correlation between reducibility of catalyst and the mechanism of CO + NO reaction. 195 NOEA 2011 Zakopane 4-7 September 2011 Table 1. The catalytic performance ofFefiiBEA (x = 0.3 -10 Fe wt. %) samples x (wt. %) 0.3 1.0 2.0 4.0 10 Tso (°C) 430 370 410 414 405 Selectivity* to N2 36 42 37 48 62 ' Selectivity at the temperature of 50% conversion (T50) of CO Fig.l. TPR-CO profile and CO conversion for Fe/^iBEA catalyst The mechanism of the reaction (1) can be considered as occurring in two stages. In the first, the reduction with CO of (Fe O)SᵢBEA to (Fe)SjBEA species probably takes place: (Fe O)$ᵢBEA + CO —» (Fe)siBEA + CO₂ (5) It explains the similar course of TPSR and TPR-CO processes. In the second one the direct decomposition of NO on the reduced form (Fe)SᵢBEA occurs, simultaneously restoring (Fe O)ₛᵢBEA species: NO + (Fe)SᵢBEA -» (Fe....O)SᵢBEA + Vi N₂ (6) The decomposition is efficient as long as the iron species in the reduced form remain. Their oxidation leads to the catalyst deactivation, which is responsible for a low stability of the catalysts under study in the reaction. [1] H.H. Chen, S.C. Shen, X. Chen, S. Kawi, Appl. Catal. B 50 (2004) 37 [2] P. Balie, B. Geiger, S. Kureti, Appl. Catal. B 85 (2009) 109 [3] J. Janas, J. Gurgul, R.P. Socha, T. Shishido, M. Che, S. Dźwigaj, Appl. Catal. B 91 (2009) 113 [4] S. Dźwigaj, J. Janas, T. Machej, M. Che, Catal. Today 119 (2007) 133 [5] I. Hnat, I. Kocemba, J. Rynkowski, T. Onfroy, S. Dźwigaj, Catal. Today, 2011 in press 196 NOEA2011 Zakopane 4-7 September 2011 PS36 Preparation and characterization of T1O2 based plasma sprayed catalytic coatings for NOX abatement V. SNAPKAUSKIENE¹, V. VALINCIUS¹ ¹ Lithuanian Energy Institute, Plasma Processing Laboratory, Breslaujos 3, LT-3035 Kaunas, Lithuania, e-mail: vilma@mail.lei.lt Il is initial part of a systematic study on the preparation and catalytic performance on metal oxide catalysts for the CO + NOX redaction. As our previous works have shown, catalytic coatings, deposited by plasma spray technology from active component CuO, reduce effectively the amount of CO in the exhaust gas (Snapkauskiene et al. [1]). The aim of further work is to select catalyst for NOK redaction. For this reason TiO₂ and Ni powder were incorporated additionally and in the first instance the system active layer-substrate was analysed to define the phase, morphology and roughness of new composition coatings. The catalytic coatings 90 pm of thickness were prepared by plasma spraying (power of plasma torch 35 kW, arc current 165 A, enthalpy 955 kJ/kg, reactor chamber diameter 10 mm, spraying distance 120 mm, plasma forming gas - air) on heat-resistant foils of FeCrAl type as a support. The support was covered with an active layer consisting of various mixture of 10-15 wt.% TiO₂ (anatase, 325 mesh; Aldrich), 10 wt.% Cu (325 mesh; Alfa Aesar) and 10 wt.% Ni (400 mesh; Alfa Aesar) with aluminium hydroxide in balance. All coatings were healed in air at 560°C for 1.5 h. The surface morphology and microstructure of the obtained samples was studied by scanning electron microscope (ESEM) Quanta 200 FEG (FE1 Ltd, Eindhoven, Netherlands), coupled with an energy-dispersive X-ray microanalysis (EDX) spectrometer Quantax 200 (Broker, Germany). The weight percent concentrations of individual surface precipitates have been calculated automatically by EDX software. The analysis of images was done with the ImageJ software. The XRD patterns of the synthesized and healed coatings were recorded with a conventional Bragg-Brentano geometry (0 - 20 scans) on a DRON-6 automated diffractometer equipped with a secondary graphite monochromator. Cu Ka radiation (k = 1.541838 A) was used as a primary beam. The patterns were recorded from 5 to 70° 20 in steps of 0.02° 20, with the measuring time of 0.5 s per step. The surface roughness of coating layers was measured by surface analyzer-profilometer Hommel Tester T500 (Germany). Analysis of SEM views of plasma sprayed coatings showed, that all coatings are characterized by homogeneous and dense structure (Fig. 1). The distribution of pores and voids is quite homogeneous, but also irregularly agglomerated metal oxide layers are formed. The morphology of all samples is more similar than different despite of the different composition of started powder. After the coatings heating at the temperature of 560°C, a positive phenomenon was observed when the surface of voids in active layer has been on the increase. EDX mapping images showed quite even distribution of active components in the washcoat. As it can be seen in Fig. 1, the roughness profiles of the as-sprayed surfaces obtained by traversing across the test surfaces using a profilometer are rather similar independent of whether the surface is fresh or healed. By the data presented the main parameter of surface roughness Rₐ of metal oxide coatings varies from 3.4 pm to 5.2 pm. The less roughness is typical for coatings with higher content of titania. The maximum roughness, i.e. the difference between the roughness maximum depth and maximum height, varies from 25 pm (15 wt.% TiO₂) to 43 pm (15 wt.% TiO₂/10 wt.% Cu/10 wt.% Ni). This parameter depends significantly not only on the number of coating layers, but also on the jet outflow regime, the flow rale of the plasma-forming gas, the applied power or the average bulk temperature, and the spraying distance (Prancvicius at al. [2]). Qualitative EDX analyses are in agreement with XRD results. The XRD patterns confirmed a titanium dioxide phase of all tasted simples and showed presence of two modifications - rutile and anatase with tetragonal crystal systems. Also results on XRD analysis of catalytic coalings show the 197 NOEA2011 Zakopane 4-7 September 2011 domination of pure copper and copper oxide Cu₂O as well as pure nickel and nickel oxide NiO, respectively. Heated simples do not show important differences in diffraction peaks. Figure 1. SEM micrograph (above) and surface profile (down) of fresh and heated coatings According to obtained results all new coatings are suitable for the analysis of catalytic processes. The multitubular catalytic monolithic reactors were manufactured of these coatings on the purpose to test it for the NOX redaction in our improved experimental equipment with a reactant mixture containing 2000 ppm of NO, 5% of CO, 21 % of O₂ and nitrogen as balance. 198 NOEA2011 Zakopane 4-7 September 2011 Postdoctoral fellowship is being funded by European Union Structural Funds project "Postdoctoral Fellowship Implementation in Lithuania [ 1 ] V. Snapkauskiene, et al., Catal. Today (2011), doi: 10.1016/j.cattod.2011.02.023 [2] L. PraneviCius, L.L PraneviCius, P. Valatkevicius, V. ValinCius. Surf. Coat. Technol. 123 (2000) 122 too NOEA20I1 Zakopane 4-7 September 2011 PS37 MgF2-MgO system as a potential support for NiO catalysts for NOX reduction by propene M. ZIELIŃSKI¹’, I. TOMSKA-FORALEWSKA¹, M. PIETROWSKI¹, M. WOJCIECHOWSKA¹ ¹ Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland *e-mail: mardok@amu.edu.pl Nitric oxides (NOX) are the most commonly encountered air pollutants, causing acid rain and climate changes. These pollutants are emitted into the atmosphere mainly from oil/coal-fired furnaces and automobile exhaust. In recent years, much attention has been focused on the removal of these air pollutants because of the pressure of stricter regulations concerning the environment protection [1,2], Selective catalytic reduction of NO by hydrocarbons (HC-SCR) is a potential method to remove NO from exhaust gases. The performance of zeolites, metallic and oxide systems in this process has been widely tested. In respect to vehicles, a well-established technology for NOX, CO and hydrocarbons emissions control is based on the three-way catalyst (TWC). In a conventional three-way catalytic converter, noble metals such as Pl, Pd (both effective in oxidizing CO and hydrocarbons) and Rh (responsible for NOX reduction) are commonly used. Due to the high costs of precious metals, considerable efforts have been made to develop catalysis using of cheaper transition metals and their oxides. One of the most active metal oxide in the process of deNOₓ is NiO. The NiO/support catalysts exhibit high activity both in NO reduction by CO under stoichiometric conditions in the absence as well as in the presence of oxygen and in NO reduction by hydrocarbons. This paper reports NiO/MgF₂-MgO activity in the NO+C₃H₆+O₂ reaction depending on properties of the support. The MgF₂-MgO system is tested as a potential support of nickel oxide catalysts in the NO+C₃H₆+O₂ reaction depending on the MgO/MgF₂ ratio in the support and the reaction conditions. The study was performed at temperatures ranging from 250 to 475°C in the reducing, oxidizing and stoichiometric conditions. The activity of the nickel oxide catalysts was compared to NiO/MgF₂ and NiO/MgO. Synthesis of supports The MgF₂ and MgF₂-MgO supports with different MgO content were obtained in the reaction of basic magnesium carbonate (4MgCO₃Mg(OH)₂-5H₂O) powder with controlled amounts of aqueous solution of hydrofluoride. The amount of hydrofluoride solution was chosen to ensure 0 , 40, 60 and 100 mol.% of MgF₂ in the support. The suspension obtained was evaporated then dried at 80°C for 24h and calcined under the air flow at 400°C for 4h. Synthesis of nickel catalysts MgO, MgF₂-MgO and MgF₂ supports, calcined at 400°C were impregnated with an aqueous solution of nickel(II)-nitrale hexahydrate in the amount ensuring 1 wt.% nickel in the catalysts. The samples, were dried at 110°C for 24h then calcined at 400°C for 4h in air. Supports and catalysts characterization The supports and the catalysts were characterized by the low-temperature adsorption of nitrogen, X-ray diffraction, thermo-gravimetric analysis, temperature-programmed reduction. Catalytic lest The reaction of NO + C₃H₆ + O₂ was performed by a continuous method. The reacting gases (1 vol.% of NO in He, I voi.% of propene in He and 5 vol.% of O₂ in He) were flown al the total flow rate of the reaction gases 50cm³/min through a quartz reactor filled with O.lg of the catalyst. In order to remove water, before reaction catalysts were activated in helium at 400°C during Ih. The reaction was run at temperature range 250-475°C. The activities of the catalysts were determined in different reaction conditions described by the parameter R defined by Tanaka et al., [3]: Rcl reducing conditions, R=1 stoichiometric and R>l oxidizing. The reaction products were analyzed using Carlo Erba 6000 GC 201 NOEA 2011 Zakopane 4-7 September 2011 equipped with 2m long column filled with 13 X molecular sieves (2/3) and chromosorb 104 (1/3). The catalytic activity was presented as apparent rate - r, (pmolN₍//JmolNₗh) - calculated for the total Ni content in a catalyst (1 wt.%). This paper reports the results of a study on the structure of nickel oxide supported on MgF₂-MgO of different composition and pure MgF₂ and MgO. The activity of the nickel oxide catalysts containing I wt.% Ni supported on MgF₂ and MgO were compared with that of the nickel catalyst obtained by impregnation of the other supports - A1₂O₃, SiO₂ - Figure I. According to the results the most active were the catalysts supported on MgF₂, although with increasing temperature their activity decreased as a result of the competitive propene oxidation reaction. The study was performed at temperatures ranging from 250 to 475°C in the reducing, oxidizing and stoichiometric conditions. The activity of the NiO/MgF₂-MgO catalysts was compared to those of Ni()/MgF₂ and NiO/MgO. The highest activities are obtained for the catalysts supported on pure MgF₂ especially in the reducing conditions. Mixed system MgF₂-MgO gave a support on which nickel revealed much higher activities in NO reduction both in reducing and in oxidizing conditions compare to NiO/MgO catalyst. Figure 2 presents the activity of the nickel catalysts versus the content of MgF₂ in the support for different R values. The NiO/MgF₂-MgO catalysts were more active in the reducing conditions and their activities increase with increasing of MgF₂ content in the mixed MgF₂-MgO supports. At an excess of oxygen (oxidizing conditions), their activities decreased. Figure I. Catalytic activity of NiO phase supported on different supports in NO reduction by propene as a function of temperature (R=0.4) 202 NOEA201I Zakopane 4-7 September 2011 Figure 2. Catalytic activity of nickel oxide catalysts in the reaction NO+CjH₍,+O₂ at 375" C for different compositions of the reaction mixture We thank the Polish Ministry of Scientific Research and Information Technology for financial support under the projects N N204 141339 and N N204 214140. [11 Worldwide Fuel Charter, Fourth Edition, September 2006 [2] Official Journal of the European Union, REGULATION (EC) No 715/2007 OF THE EUROPEAN PARI JAMENT AND OF THE COUNCIL of 20 June 2007 [3] T. Tanaka, K. Kokota, N. Isomura, H. Doi, M. Sugiura, Appl. Catal. B 16 (1998) 199 203 NOEA2011 Zakopane 4-7 September 2011 PS38 Raman spectroscopic studies of the oxide Ni-Fe-Cr catalysts for NO decomposition A. WESEŁUCHA-BIRCZYŃSKA¹, M. KOZICKI¹, M. NAJBAR¹ ¹ Jagiellonian University, Faculty of Chemistry, 3 Ingardena St., 30-060 Kraków, Poland NOX (NO and NO₂) belong to the most dangerous air pollutants. Ammonia is commonly used to remove NOX from off-gases of stationary sources of emission. It is also applied for their removal from Diesel engine exhausts. However, ammonia as a reducer has several drawbacks; it is corrosive, relatively expensive and poisonous. Therefore, there is a great effort to replace ammonia by another reducer or to remove NO by direct decomposition to dinitrogen and dioxygen. A current paper concerns Raman spectroscopic investigations of oxide phases forming on the surface of acid-resistant steel foil in the course of its oxidation and showing good activity in the direct NO decomposition. Oxide phases were formed on the acid resistant austenitic steel (1 Hl8N9T/1.4541) tubes and resistant austenitic steel (OH 18N9/1.4301) sheets of foil by thermo-programmed heating from room temperature up to 850 °C in air or in the stream of air or oxygen and then annealing at the final temperature for and 4 hours, respectively. Heating and annealing were performed once or several times to obtain oxide layers of different temperatures. Powder of oxides was scraped from the oxidized tubes. However, oxidized foils were investigated directly in spectrometer. Raman spectra were collected using Raman Renishaw inVia micro-spectrometer working in confocal mode. Samples were excited with 785 nm laser line of HP NIR diode laser. The laser power was low to ensure that it not destroys sample. In a figures 1 (a-c) the micrographs of the chosen areas of oxide sample scraped from the tube annealed at 650 °C are presented. Figure Id demonstrates Raman spectra collected from the micro areas marked in the Figures 1 a-c. A scale grown on the surface of the acid resistance steel tube is composed of a-Fe₂O₃ [1,2] and spinel phase (Ni,Fe)(Fe,Cr)₂O₄ [3-6]. The position of the main peak of the spinel phase depends on the content of chromium in tetrahedral positions and content of nickel in octahedral one. It shifts towards higher wavenumbers with the increase of Cr as well as Ni content. The reduced a-Fe^ phase as well as spinel phases are known to be active in NO decomposition. The coexistence of both phases may increase this activity due to strains on the phase boundaries enhancing mobility of the lattice oxygen atoms. Further increase of the activity of the scale may be caused by the formation of Cr/ Fe₂O₃ solid solution and/or by Ni²⁺ substitution for Fe²⁺ and Cr³* substitution for Fe³* in spinel phase. Raman spectra of the rust on the oxidized foil from OH 18N9/1.4301 sheets resemble those of the powder scraped from 1H18N9T/1.4541 tubes. The most visible difference is the position of the main peak of the spinel phase. This position is closer to that of Fe₃O₄. It reveals that several oxidation procedures are needed to introduced chromium and/or nickel to magnetite. 205 NOEA2011 Zakopane 4-7 September 2011 [1] S.H. Shim.T.S. Duffy, Raman spectroscopy of Fe2O₃ to 62 GPa, Am. Mineral., 87 (2001) 318-326 [2] MJ. Massey, U. Baier, R. Merlin, W.H. Weber, Effect of pressure and isotopic substitution on the Raman Spectrumof a-Fe2O₃: Identification of two-magnon scattering, Phys. Rev. B41 (1990) 7822-7827 [3] O.N. Shebanova, P. Lazor, Raman spectroscopic study of magnetite (FeFe₂O₄): a new assignment for the vibrational spectrum, Journal of Solid State Chemistry 174 (2003) 424-430 [4] M. Chen, J. Shu, X. Xie, H.K. Mao, Natural CaTi2O₄-structured FeCr₂O₄ polymorph in the Suizhou meteorite and its significance in mantle mineralogy, Geochim. Cosmochim. Acta, 67 (2003) 3937-3942 [5] B. J. Reddy, R. L. Frost, Spectroscopic characterization of chromite from the Moa-Baracoa Ophiolitic Massif, Cuba, Spectrochim. Acta A 61 (2005) 1721-1728 [6] A. Ahlawat, V. G. Sathe, Raman study of NiFe^ nanoparticles, bulk and films: effect of laser power, J. Raman Spectrosc. (2010), (wileyonlinelibrary.com) DOI 10.1002/jrs.2791 206 NOEA2011 Zakopane 4-7 September 2011 PS39 Metal-supported sulfated ceria-zirconia catalysts for the SCR of NOX by ethanol: performances and mechanisms A. WESTERMANN¹, B. AZAMBRE¹*, A. KOCH¹ ¹ Laboratoire de Chimie et Methodologies pour I’Environnement (LCME), Institut Jean-Barriol, Universite Paul Verlaine - Metz, Rue Victor Demange 57500 Saint- Avoid, France, *e-mail: bazambre@.univ-metz.fr In our last study [ 1|, we aimed to investigate the SCR performances and mechanisms of novel sulfated CeₓZrₗ.IO₂ (SCZ) catalysts using ethanol as reductant. Though these catalysts displayed an intrinsic lesser activity than the widely-studied Ag/Al₂O₃ and Ag- or Ba-Y catalysts [2], we have shown that the DeNOx yield was strongly dependent on the Ce molar fraction of SCZ catalysts and reached a maximum for x = 0.5 (50 % DeNOx al 350°C) [I], By contrast, the parent sulfated zirconia (SZ) was found to be rather inactive, and sulfated ceria (SC) was less selective than SCZ catalysts, due to its ability to promote the non-selective oxidation of ethanol and the formation of toxic by-products, namely HCN [I], Also, it was noticed that the sulfation treatment of the parent CZ materials partially inhibited the total oxidation of the reductant, rather promoting its partial oxidation to CₓHyOz species such as acetaldehyde, which is very selective for the NOx reduction to N₂. Hence, sulfated ceria-zirconia have the required characteristics to be employed as supports for EtOH-SCR, and their activity may be possibly further tuned by the help of supported metal promoters, similarly to what we observed previously when these catalysts were investigated for the SCR of NOx by methane [3]. The aim of this article is two-fold: (i) to compare the ethanol-SCR performances of several supported metal catalysts (Pd, Co, Ag on SCZ) with the sulfated support alone; (ii) to assess the influence of the promoter on the different possible reaction pathways for ethanol-SCR. The parent Cco.₂Zr₀₈0₂ (CZ28) support with tetragonal structure was supplied by Rhodia and had a SBET of 184 m²/g. The sulfated SCZ28 support was obtained by soaking the CZ nanopowder into 0.5 M H₂SO₄, subsequent drying at 70°C and calcination at 500 °C. Impregnation of SCZ28 with PdCl₂, Co(NO₃)₂ and AgNO₃ precursors previously dissolved in NH₃, was carried out in order to achieve Pd (0.24 %M), Co (1.03 %M) and Ag (3%w) loadings. Catalytic tests on pre-treated catalysts (500°C under He/O₂) were carried out both in ramp (TPSR) and isothermal modes in a quartz reactor in the 25-500 °C range using a standard mixture (unless otherwise staled) of NO (1900 ppm) + EtOH (3020 ppm) + O₂ (5 %). The detection/quantification of the reactants/products (more than 10) was done using a FTIR gas cell (2 m) coupled to a Varian Excalibur 4100 FTIR spectrometer and a home-made methodology. N- and C- intermediates adsorbed on the surface were monitored according to the temperature and reaction conditions using a heatable reaction cell coupled to a DRIFTS optical accessory. Bulk and surface characterizations of the catalysts were achieved using TGA, XRD, DRS-UV-Vis, HRTEM-EDX and DRIFTS of CO adsorption al 25 °C. The nature of promoting species (Pd, Co, Ag) deposited on SCZ28 was investigated first. Prior to SCR catalytic tests, the Pd and Co promoters were found to exist on SCZ surfaces as highly dispersed species, namely |Pd(O)„...H|x⁺ and [Co(O)ₙ...H]x⁺, with enhanced Lewis acidity due to the withdrawing effect of sulfate groups. By contrast, a new Ag₂SO₄ phase was detected by XRD for the Ag catalyst, which coexists with well-dispersed Ag⁺ and Agₙx⁺ species. By comparison with the SCZ28 support alone, the NOx conversion on the Co-supported catalyst was somewhat similar (about 40% conversion, namely to N₂) but slightly displaced the DeNOx window towards high temperatures (Fig. 1A). By contrast, the presence of Pd and Ag promoters was found to be more detrimental (Fig. I A), as the DeNOx yield decreased by around 12% (42 to 30%). It is worth noting that these results were not that first expected, since the same promoters (especially the Pd one) resulted in a strong enhancement of the DeNOx activity when methane was used instead of ethanol for 207 NOEA2011 Zakopane 4-7 September 2011 NOx-SCR [3]. Hence, this proves that Cex⁺ species existing on the SCZ28 support are probably the true active sites under the present conditions, i.e. when ethanol is used as reductant. Figure 1. A) Effect of the promoting species (Pd, Co, Ag) on the NOx conversion under steady-state conditions (NO +C₂HSOH +O₂); B) In situ DRIFTS spectra of adsorbed intermediates at 350 °C for SCZ28 and Ag/SCZ28 Indirect information about the role of the different promoters and their states under SCR conditions was obtained by comparing: (a) the NOx conversions under TPSR conditions (increasing temperatures, not shown here) with those obtained under steady-state conditions at decreasing temperatures (after TPSR, Fig. 1A)); (b) the temperature-dependence of the main products formed in the gas phase (acetaldehyde, CO, CO2, methane, ethene, ethylnitrite...) or in adsorbed state (ethoxy, acetate/enolate, acetyl, -NC, -NCO, amine-like...). For the promoters investigated, their addition inhibited, at least partially, the Ce active sites and/or the selective oxidation of ethanol to CₓHyOz species, which in turn decreases the SCR activity. More peculiarly, it is worth noting that the DeNOx activity for the Ag-SCZ28 catalyst decreased slightly when switching from TPSR conditions (48% at 415 °C) to isothermal ones (30% at 360 °C). Here, this apparent “deactivation” seems to be related to a decrease in the availability of acetaldehyde (the most selective reductant species) under steady-state conditions, itself due to an in situ reduction of cationic 208 NOEA 2011 Zakopane 4-7 September 2011 Ag species to metallic ones during the test. Such changes in the nature of Ag species were confirmed by XRD and TGA analyses on the spent Ag catalyst, which have pointed out the disappearance of the Ag₂SO₄ phase under SCR conditions. The decreased NOx conversion in presence of 0.24%WIPd (30% at 350 °C) should also be related to its selectivity for the oxidation of CH₃COO' intermediates formed upon CH₃CHO adsorption, witnessed by the presence of CO₂ and CH₄ in rather high amounts. Finally, this study was completed by the DRIFTS investigation of the SCR mechanism on the support and the Ag-containing catalyst under different conditions. The reactions between nitrates ad-species and some activated forms of HC species (namely from acetaldehyde) was found to be involved directly into the formation of crucial intermediates such as HCN, HNCO, and other ad-species (-CN, -NC, -NCO, NH₄⁺). These intermediates further react with NO and/or O₂ to yield N₂ via mechanisms rather similar to NH₃-SCR. [1] A. Westermann, B. Azambre, Catal. Today (2010) doi: 10.1016/j.cattod.2010.10.071 [21 Y.H. Yeom, M. Li, W.M.H. Sachtler, E. Weitz, J. Catal. 246 (2007) 413 [3] B. Azambre, L. Zenboury, P. DaCosta, S. Capela, S. Carpentier, A. Westermann, Catal.Today (2011) doi: 10.1016/j.cattod.2010.12.026 INDEX A ADAMOWSKAM., 127 ADAMSKI A., 101, 107, 123 ADOUANED.,61, 115 AISSATA.,45, 83, 111 AIBARAZ1 A., 71 ASCASO S„ 77 AZAMBREB.,81, 117, 165,207 B BANAŚ J., 117 BARTKEJ., 13 BARTOLOMEU R„ 81 BARTOVA Ś., 63, 183 BASSILJ.,71 BERTOLOR.,81 BIAŁAS A., 163 BIELAŃSKA E„ 25, 119 BOICHUK T, 49 BONZI R„ 59 BOUTROS M„ 71 BUZANOWSKI M. A., 23 C CAMPA M.C., 149 CAMRAJ., 25, 121, 163 CAPELAS., 127 CARRE S„ 67 CASTOLDI L„ 59 CHMIELARZL., 33, 123, 141 CHMIELEWSKI A. G„ 17 CHO B. K„ 55 CHOI J.-S., 63 CHROMCAKOVA Ź., 155 COURCOT D„ 45, 83, 111 CRELLIN C. C„ 55 ĆWIKŁA-BUNDYRAW., 47, 131 D Da COSTAP., 21,41,61,71,81,89, 115, 127, 165 DARCY P„ 61,89 DHAINAUTE, 67 DJEGA-MARIADASSOU G„ 19,173 DOBIJA A., 135 DOBROSZ-GÓMEZ I., 139,143 DUDEK B„ 123 DUJARDIN C„ 67, 95 DUTKIEWICZ J., 25, 121, 137, 187 DZIEMBAJ R„ 123, 141 DŹWIGAJ S„ 43, 59, 195 E EMMEZE., 189 F F1UKM., 107 FOIXM.,21 FONTALVOJ., 143 FORZATTI P„ 59 FOUCHALN., 89 G GAGNEPA1N L„ 127 GALVEZ M. E„ T1 GHIOTTI G., 59 GIL B„ 27, 29, 107 GOMEZ-GARCIA M. A., 139, 143 GÓRA-MAREK K„ 147 GRADOŃ B„ 99 GRANGER P„ 67,95 GRZYBEK T„ 37 GUYON C.,21 H HENRIQUES C.,81 HEO I., 55 HILDEN D. L„ 55 HNATI., 195 I INDOVINA V, 149 J JANAS J., 43 JAN1GAS., 137, 187 JEANDELX., 115 J1RATOVA K., 97, 155 JODŁOWSKI P„ 27,29 K KANTCHEVAM., 151 KARASKOVA K., 155 KIM M. K„ 55 KIM P. S„ 55 211 KIRIENKO R, 49, 191 KLINIK J., 37 KNAPIK A., 29 KOCEMBAI., 139, 195 KOCH A., 81, 207 KOĆIK., 159 KOCI P„ 63, 183 KOŁACZKOWSKI S., 27,29, 181 KOŁODZIEJ A., 27, 29 KONKOL M„ 93 KORNELAK P, 137, 163, 165, 167, 187 KOTARBA A., 91, 169, 177 KOVANDA E, 97 KOWALIK P„ 93 KOZICKI M„ 25, 119, 121, 137, 171, 187,205 KREJCIKOVA S„ 159 KRUKJ., 93 KRZTOŃ A., 173, 193 L ŁABANOWSKA M., 167 ŁACNY Z., 159 ŁAMACZA., 173, 193 LANDI G„ 87 LASEK J„ 99 ŁASOCHA W., 25, 135, 163,175 LAZARO M. J„ 77 LEEJ.-H., 55 LEGUTKO P, 169 LICKIJ., 17 L1ETTI L., 59 LISI L., 87 LITYŃSKA-DOBRZYŃSKAL.,25, 171 ŁOJEWSKA J., 27, 29, 181 M MACYKW., 167 MAKOWSKI W., 29 MANIAK G„ 91, 177 MANIGRASSOA.,89 MARCEW1CZ-KUBA A., 179 MAREK M., 63, 183 MATUSIEWICZA., 123 Mc CLYMONT D., 27,29, 181 MICHALIK M„ 123 MICHALSKA K., 93 MILANOVAM., 151 MOLENDA M„ 141 MOL1NER R„ 77 MORANDI S., 59 MOTAK M„ 37 MRAĆEK D„ 183 N NAJBAR M„ 25, 117, 119, 121, 137, 163, 165, 167, 171, 175, 187,205 NAM I.-S., 55 NAZARCZUK I., 25, 119, 137, 167, 175, 187 NAZ1MEK D„ 47 NI X., 95 NITEK W., 135 O OBALOVA L„ 97, 155, 159 OCHOŃSKA J„ 27, 29, 181 OLSON K., 55 ORLYK S„ 49 ÓZENSOY E„ 69, 189 P PAŁKOWSKA E„ 25 PALOMARES A. E„ 31 PARTRIDGE W., 63 PAWELEC A., 17 PETELENZ B., 11 PIETRASZEK A., 165 PIETROGIACOMI D„ 149 PIETROWSKI M„ 201 PIHLJ.,63 PIRONE R„ 87 PISKORZ W., 91, 177 PLATE, 183 POPOVYCH N„ 191 R RADLIK M„ 193 RAFALSKA-ŁASOCHAA., 15, 175 RAS1ŃSKA D„ 163 RENEME Y, 67 RIBEIRO M.E, 81 ROGULSKA A., 29 ROJEK W., 43 RUSSO G„ 87 RUTKOWSKA M„ 123, 141 RYNKOWSKI J„ 195 RYNKOWSKI J. M„ 139, 143 S SALAUN M„ 127 SAMOJEDEN B„ 37 SEDA §ENTURK G„ 69 SIFFERT S„ 45, 83, III SNAPKAUSKIENE V, 197 SOJKA Z., 91, 101, 107, 169, 177 212 SOLCOVA O., 159 SOLOVIEV S„ 49,191 STAN K., 171 STARCK J., 115 STELMACHOWSKI P.,91, 169,177 STOLECKI K„ 93 STUDENTOVA S„ 155 SU D„ 163 SUNY., 17 SZYNKOWSKAM. I., 139 T TARACH M„ 107 TATOULIANM.,21 TOBAM., 167 TOBIAS I., 77 TOMSKA-FORALEWSKA I., 201 TORTORELLI M„ 87 TRICHARD J.-M., 53 TUREK W„ 193 V VAL1NC1US V., 197 VOVK E., 69, 189 W WĘGRZYNA., 123 WESEŁUCHA-BIRCZYŃSKA A., 25, 163, 205 WESTERMANN A., 81,207 WITMAN S„ 17 WOJCIECHOWSKA M„ 123,201 WU Y„ 95 Z ZAITZM.M., 141 ZAJĄC W., 101 ZAPAŁA P., 107 ZASADAF.,91, 101, 177 ZENBOURY L„ 165 ZHANG W„ 163 ZHAO Z„ 75 ZIELINSKI M., 201 Z1MEK Z., 17 ZIMOWSKA M„ 119 213