Reactivity of Extra-framework Species of USY Zeolites in Alkaline Medium Full article
Journal |
Zeitschrift fur Anorganische und Allgemeine Chemie
ISSN: 0044-2313 , E-ISSN: 1521-3749 |
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Output data | Year: 2011, Volume: 637, Number: 1, Pages: 75-82 Pages count : 8 DOI: 10.1002/zaac.201000273 | ||||||||||||
Tags | Aluminum, Alumosilicates, NMR spectroscopy, Silicon, Synthesis design, Zeolites | ||||||||||||
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Abstract:
Zeolites of type USY (ultra-stable Y) were obtained by steaming of NH4NaY modification. Samples were modified by subsequent alkaline treatment in KOH solution. USY and USY-KOH were characterised by chemical element analysis, XRD, IR, 29Al and 29Si MAS NMR spectroscopic measurements. Correct silicon to aluminium ratios (Si/Al) were determined by XRD and IR (double ring vibration wDR) data whereas values calculated according to data of 29Si MAS NMR and IR spectroscopy (asymmetrical TOT valence vibration wTOT) appeared to be too high., In the latter case, the signals of the zeolite framework were strongly superimposed by that of extra-framework silica gel (EFSi) formed during steaming. It was found that alkaline leaching induces desilication of silicon-rich area of the zeolite framework and partial dissolution of EFSi. Silicate ions of both react with likewise dissolved extra-framework aluminium (EFAl) to form X-ray amorphous aluminosilicate. Consequently, the superposition of the 29Si MAS NMR signals of the zeolite framework by silica gel was reduced for Q4(0Al) but increased for Q4 (2Al) and Q4(3Al) structure units. A reinsertion of EFAl into the zeolite framework has not been observed.
Cite:
Lutz W.
, Bertram R.
, Heidemann D.
, Kurzhals R.
, Rüscher C.
, Kryukova G.
Reactivity of Extra-framework Species of USY Zeolites in Alkaline Medium
Zeitschrift fur Anorganische und Allgemeine Chemie. 2011. V.637. N1. P.75-82. DOI: 10.1002/zaac.201000273 WOS Scopus РИНЦ
Reactivity of Extra-framework Species of USY Zeolites in Alkaline Medium
Zeitschrift fur Anorganische und Allgemeine Chemie. 2011. V.637. N1. P.75-82. DOI: 10.1002/zaac.201000273 WOS Scopus РИНЦ
Dates:
Submitted: | Jul 7, 2010 |
Accepted: | Sep 8, 2010 |
Published online: | Sep 8, 2010 |
Published print: | Jan 1, 2011 |
Identifiers:
Web of science | WOS:000285788600014 |
Scopus | 2-s2.0-78650716525 |
Elibrary | 16725535 |
Chemical Abstracts | 2010:1620127 |
Chemical Abstracts (print) | 154:420486 |
OpenAlex | W2108258572 |