Supported vanadium oxide catalysts: quantitative spectroscopy, preferential adsorption of V4+/5+, and Al2O3 coating of zeolite Y
Article Abstract:
Diffuse reflectance spectroscopy and electron spin resonance spectroscopy were used in determining the amount of V4+ and V5+ ions in vanadium oxide catalysts. These catalysts have been prepared by the incipient wetness method. The preferential adsorption of both types of ions on SiO2, Al2O3 and USY has also been investigated. Results indicate the presence of V4+ ions on SiO2, Al2O3 and USY surfaces as distorted octahedral species. The supported V5+ species are always in tetrahedral coordination. Both types of ions are preferentially adsorbed on Al2O3 and are mobile on hydrated surfaces.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 1998
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Relating structure and chemical composition with lewis acidity in zeolites: a spectroscopic study with probe molecules
Article Abstract:
The experiments were done where spectroscopic studies were performed on the Lewis acid sites in FAU and MFI zeolites with different nonframework Al content. The results show that the frequency shifts and the relative intensities of these peaks were correlated with the structure type and the nonframework Al amount.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 2001
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Reactivity descriptors and rate constants for acid zeolite catalyzed ethylation and isopropylation of benzene
Article Abstract:
The acid zeolite catalyzed and isopropylation of benzene with ethene and propene is investigated at the B3LYP/6-31G* level of calculation with T4-cluster representing the bronsted acid site of the zeolite. Transition structures, and products, a kinetic and a sensitivity analysis were used to model the reactions.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 2003
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