Hierarchic zeolites: zeolite ZSM-5 desilicated with NaOH and NaOH/tetrabutylamine hydroxide

2013
journal article
article
143
cris.lastimport.wos2024-04-09T19:24:46Z
dc.abstract.enThe desilication of zeolite ZSM-5 (Si/Al = 31.6) was performed by the treatment with NaOH of various concentrations (0.1, 0.2, 0.5 and 1 M) and with NaOH/TBAOH mixtures of various concentrations and ratios between both bases. The information on the composition of both bulk and surface was obtained by ICP-OES and XPS, respectively. It has been found that diluted NaOH solutions extracted Si equally from the surface and bulk of ZSM-5. In more concentrated NaOH the desilication from the bulk was more effective than from the surface. The MAS NMR studies showed that Si(4Si,0Al) was less stable and was removed from the zeolite structure before Si(3Si,1Al). Higher stability of Si(3Si,1Al) was explained by the repulsion of AlO4- and OH-. According to the IR results the desilication, leading to mesopore formation, increased distinctly the amount of Si-OH on mesopore walls and also the contribution of acidic Si-OH-Al. Calcination of desilicated zeolite at air atmosphere resulted in a significant loss of tetrahedral Al due to the "steaming" of zeolite with water physisorbed in mesopores facilitated by lower stability of framework injured by desilication. Both NMR and IR studies suggested that the stability of Si atoms in the zeolite framework increased in the following order: (SiO) 3Si-OH < (SiO)3Si-OSi < (SiO)3Si-OAl. Porosimetric experiments evidenced that the NaOH treatment produced mesopores with very broad pore size distribution (a majority of pore diameters was close to 20 nm). The desilication with the NaOH/TBAOH mixtures produced mesopores of higher surface area and pore volume but of smaller diameter than with NaOH alone. We suppose that in the presence of TBAOH a larger number of narrower pores is formed, or narrow pores penetrate zeolite crystal more deeply.pl
dc.affiliationWydział Chemii : Zakład Chemii Nieorganicznejpl
dc.affiliationWydział Chemii : Zakład Technologii Chemicznejpl
dc.affiliationWydział Chemii : Pracownia Spektrometrii w Podczerwienipl
dc.contributor.authorTarach, Karolina - 103685 pl
dc.contributor.authorWach, Anna - 126105 pl
dc.contributor.authorOlejniczak, Zbigniewpl
dc.contributor.authorKuśtrowski, Piotr - 129800 pl
dc.contributor.authorDatka, Jerzy - 127692 pl
dc.date.accessioned2015-01-26T14:02:21Z
dc.date.available2015-01-26T14:02:21Z
dc.date.issued2013pl
dc.description.additionalNa publikacji autorka Tarach Karolina podpisana jako Sadowska Karolina.pl
dc.description.admin[AB] Datka, Jerzy [SAP11003748] 50000141pl
dc.description.physical82-88pl
dc.description.volume167pl
dc.identifier.doi10.1016/j.micromeso.2012.03.045pl
dc.identifier.eissn1873-3093pl
dc.identifier.issn1387-1811pl
dc.identifier.urihttp://ruj.uj.edu.pl/xmlui/handle/item/2753
dc.languageengpl
dc.language.containerengpl
dc.rightsDodaję tylko opis bibliograficzny*
dc.rights.licencebez licencji
dc.rights.uri*
dc.subject.enzeolite ZSM-5pl
dc.subject.endesilicationpl
dc.subject.enNMR spectroscopypl
dc.subject.enIR spectroscopypl
dc.subject.enporosimetrypl
dc.subtypeArticlepl
dc.titleHierarchic zeolites: zeolite ZSM-5 desilicated with NaOH and NaOH/tetrabutylamine hydroxidepl
dc.title.journalMicroporous and Mesoporous Materialspl
dc.typeJournalArticlepl
dspace.entity.typePublication
cris.lastimport.wos
2024-04-09T19:24:46Z
dc.abstract.enpl
The desilication of zeolite ZSM-5 (Si/Al = 31.6) was performed by the treatment with NaOH of various concentrations (0.1, 0.2, 0.5 and 1 M) and with NaOH/TBAOH mixtures of various concentrations and ratios between both bases. The information on the composition of both bulk and surface was obtained by ICP-OES and XPS, respectively. It has been found that diluted NaOH solutions extracted Si equally from the surface and bulk of ZSM-5. In more concentrated NaOH the desilication from the bulk was more effective than from the surface. The MAS NMR studies showed that Si(4Si,0Al) was less stable and was removed from the zeolite structure before Si(3Si,1Al). Higher stability of Si(3Si,1Al) was explained by the repulsion of AlO4- and OH-. According to the IR results the desilication, leading to mesopore formation, increased distinctly the amount of Si-OH on mesopore walls and also the contribution of acidic Si-OH-Al. Calcination of desilicated zeolite at air atmosphere resulted in a significant loss of tetrahedral Al due to the "steaming" of zeolite with water physisorbed in mesopores facilitated by lower stability of framework injured by desilication. Both NMR and IR studies suggested that the stability of Si atoms in the zeolite framework increased in the following order: (SiO) 3Si-OH < (SiO)3Si-OSi < (SiO)3Si-OAl. Porosimetric experiments evidenced that the NaOH treatment produced mesopores with very broad pore size distribution (a majority of pore diameters was close to 20 nm). The desilication with the NaOH/TBAOH mixtures produced mesopores of higher surface area and pore volume but of smaller diameter than with NaOH alone. We suppose that in the presence of TBAOH a larger number of narrower pores is formed, or narrow pores penetrate zeolite crystal more deeply.
dc.affiliationpl
Wydział Chemii : Zakład Chemii Nieorganicznej
dc.affiliationpl
Wydział Chemii : Zakład Technologii Chemicznej
dc.affiliationpl
Wydział Chemii : Pracownia Spektrometrii w Podczerwieni
dc.contributor.authorpl
Tarach, Karolina - 103685
dc.contributor.authorpl
Wach, Anna - 126105
dc.contributor.authorpl
Olejniczak, Zbigniew
dc.contributor.authorpl
Kuśtrowski, Piotr - 129800
dc.contributor.authorpl
Datka, Jerzy - 127692
dc.date.accessioned
2015-01-26T14:02:21Z
dc.date.available
2015-01-26T14:02:21Z
dc.date.issuedpl
2013
dc.description.additionalpl
Na publikacji autorka Tarach Karolina podpisana jako Sadowska Karolina.
dc.description.adminpl
[AB] Datka, Jerzy [SAP11003748] 50000141
dc.description.physicalpl
82-88
dc.description.volumepl
167
dc.identifier.doipl
10.1016/j.micromeso.2012.03.045
dc.identifier.eissnpl
1873-3093
dc.identifier.issnpl
1387-1811
dc.identifier.uri
http://ruj.uj.edu.pl/xmlui/handle/item/2753
dc.languagepl
eng
dc.language.containerpl
eng
dc.rights*
Dodaję tylko opis bibliograficzny
dc.rights.licence
bez licencji
dc.rights.uri*
dc.subject.enpl
zeolite ZSM-5
dc.subject.enpl
desilication
dc.subject.enpl
NMR spectroscopy
dc.subject.enpl
IR spectroscopy
dc.subject.enpl
porosimetry
dc.subtypepl
Article
dc.titlepl
Hierarchic zeolites: zeolite ZSM-5 desilicated with NaOH and NaOH/tetrabutylamine hydroxide
dc.title.journalpl
Microporous and Mesoporous Materials
dc.typepl
JournalArticle
dspace.entity.type
Publication

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