ISSN:
1588-2837
Keywords:
Chromium-substituted silicoaluminophosphate
;
MAS NMR spectroscopy
;
acidity
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Three different molecular sieves were synthesised and characterized using31P and27Al magic angle spinning nuclear magnetic resonance (31P and27Al MAS NMR) spectroscopy and acidity measurement techniques. The synthesized solids were: a silicoaluminophosphate (SAPO-11) sample, a chromium-substituted silicoaluminophosphate (CrAPSO-11) sample and a chromium-supported SAPO-11 (Cr/SAPO-11) sample. Significant differences were observed between the CrAPSO-11 MAS NMR spectra and the spectra for the other two solids. The differences can be understood in terms of a different chemical environment for the Al(III) and P(V) ions in the molecular sieve framework, as a result of a different type of interaction, probably with substituted chromium ions in the framework. The acidity measurements were in agreement with the MAS NMR spectroscopy results, providing further evidence for the incorporation of chromium ions into the molecular sieve framework.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02475785
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