An IR spectroscopy study of Co sites in zeolites CoZSM-5

2007
journal article
article
45
cris.lastimport.scopus2024-04-07T14:37:55Z
cris.lastimport.wos2024-04-10T02:15:29Z
dc.abstract.enWe examined the status and properties of $Co^{2+}$ and $Co^{3+}$ in CoZSM-5 zeolites of various Si/Al and Co contents and activated under various conditions. CO, NO and pivalonitrile were used as probe molecules. Some information on the status of Co was also obtained by comparing the intensities of Si-OH-Al bands and the concentration of protonic sites measured with pyridine. IR studies showed that in zeolite with high concentrations of $AlO_{4}^{-}$ (of low Si/Al) practically all Co takes the form of $Co^{2+}$ exchange cations (CO band at 2204$cm^{-1}$). However, in zeolites with low $AlO_{4}^{-}$ concentrations (of high Si/Al) most Co occurs in the form of CoO (CO band at 2179$cm^{-1}$) or “oxide-like clusters” (bands at 2184 and 2194$cm^{-1}$, respectively). Experiments with co-adsorption of pivalonitrile and CO prove that all cobalt species (both in exchange positions and in “oxide-like clusters”) are situated inside zeolitic channels. The spectra of NO revealed the presence of three kinds of $Co^{3+}$ (NO bands 1940, 1955 and 1970$cm^{-1}$), presence of Co2+ mononitrosyls (NO band at 1850$cm^{-1}$) and of $Co^{2+}$ dinitrosyls (NO bands at 1815 and 1895$cm^{-1}$). Experiments on the co-adsorption of NO and CO suggested that NO can be bonded to $Co^{2+}$ in exchange cationic positions, in “oxide-like clusters” (characterized by CO bands at 2204 and 2194$cm^{-1}$), but it cannot interact with $Co^{2+}$ in 'oxide-like clusters" (CO band at 2184$cm^{-1}$) or bulk CoO (CO band at 2179$cm^{-1}$).pl
dc.affiliationWydział Chemii : Zakład Chemii Nieorganicznejpl
dc.contributor.authorGóra-Marek, Kinga - 128133 pl
dc.contributor.authorGil, Barbara - 128059 pl
dc.contributor.authorŚliwa, Michałpl
dc.contributor.authorDatka, Jerzy - 127692 pl
dc.date.accessioned2015-09-24T07:45:09Z
dc.date.available2015-09-24T07:45:09Z
dc.date.issued2007pl
dc.description.physical33-42pl
dc.description.volume330pl
dc.identifier.doi10.1016/j.apcata.2007.06.033pl
dc.identifier.eissn1873-3875pl
dc.identifier.issn0926-860Xpl
dc.identifier.urihttp://ruj.uj.edu.pl/xmlui/handle/item/15778
dc.languageengpl
dc.language.containerengpl
dc.rightsDodaję tylko opis bibliograficzny*
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dc.subject.enzeolite CoZSM-5pl
dc.subject.enIR spectroscopypl
dc.subject.ennitrosylspl
dc.subtypeArticlepl
dc.titleAn IR spectroscopy study of Co sites in zeolites CoZSM-5pl
dc.title.journalApplied Catalysis. A, Generalpl
dc.typeJournalArticlepl
dspace.entity.typePublication

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