Jagiellonian University Repository

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


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

Show full item record

dc.contributor.author Tarach, Karolina [SAP14004719] pl
dc.contributor.author Wach, Anna [USOS848] pl
dc.contributor.author Olejniczak, Zbigniew pl
dc.contributor.author Kuśtrowski, Piotr [SAP11017146] pl
dc.contributor.author Datka, Jerzy [SAP11003748] pl
dc.date.accessioned 2015-01-26T14:02:21Z
dc.date.available 2015-01-26T14:02:21Z
dc.date.issued 2013 pl
dc.identifier.issn 1387-1811 pl
dc.identifier.uri http://ruj.uj.edu.pl/xmlui/handle/item/2753
dc.language eng pl
dc.rights Dodaję tylko opis bibliograficzny *
dc.rights.uri *
dc.title Hierarchic zeolites: zeolite ZSM-5 desilicated with NaOH and NaOH/tetrabutylamine hydroxide pl
dc.type JournalArticle pl
dc.description.physical 82-88 pl
dc.description.additional Na publikacji autorka Tarach Karolina podpisana jako Sadowska Karolina. pl
dc.abstract.en 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. pl
dc.subject.en zeolite ZSM-5 pl
dc.subject.en desilication pl
dc.subject.en NMR spectroscopy pl
dc.subject.en IR spectroscopy pl
dc.subject.en porosimetry pl
dc.description.volume 167 pl
dc.identifier.doi 10.1016/j.micromeso.2012.03.045 pl
dc.identifier.eissn 1873-3093 pl
dc.title.journal Microporous and Mesoporous Materials pl
dc.language.container eng pl
dc.affiliation Wydział Chemii : Zakład Chemii Nieorganicznej pl
dc.affiliation Wydział Chemii : Zakład Technologii Chemicznej pl
dc.affiliation Wydział Chemii : Pracownia Spektrometrii w Podczerwieni pl
dc.subtype Article pl
dc.rights.original bez licencji pl
.pointsMNiSW [2013 A]: 35

Files in this item

Files Size Format View

There are no files associated with this item.

This item appears in the following Collection(s)