Further evidence of incorporation of chromium ions into the framework of silicoaluminophosphate molecular sieves

Autor:	Francisco J. Machado, Bernardo Méndez, Carmen López, M. M. Ramirez, J. Goldwasser
Rok vydání:	1999
Předmět:	Mas nmr spectroscopy Chemistry Magic angle spinning Analytical chemistry Physical chemistry Physical and Theoretical Chemistry Molecular sieve Spectroscopy Catalysis Spectral line Chromium atom Ion
Zdroj:	Reaction Kinetics and Catalysis Letters. 67:365-370
ISSN:	1588-2837 0133-1736
DOI:	10.1007/bf02475785
Popis:	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.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::166742f2643926512828e9c6439f276a https://doi.org/10.1007/bf02475785 Zobrazit plný text záznamu Full text from SpringerLink