Characterization of (V{sub 2}O{sub 5}-WO{sub 3}) on TiO{sub x}/Al{sub 2}O{sub 3} catalysts by {sup 1}H-, {sup 15}N-, and {sup 51}V-solid state NMR spectroscopy
- Boreskov Institute of Catalysis, Novosibirsk (Russian Federation); and others
Vanadium and tungsten oxide supported on TiO{sub x}/Al{sub 2}O{sub 3} catalysts have been studied by solid state NMR spectroscopy. {sup 1}H-MAS NMR spectra demonstrated that basic AlOH groups are involved in anchoring TiO{sub x} and VO{sub x} species. A certain percentage of the AlOH groups are located in positions, probably in the bulk of the alumina particles, where they remain inaccessible for interaction with titania, vanadia, or tungsten oxide. Titania modification of the Al{sub 2}O{sub 3} surface leads to formation of bridging hydroxyls, namely Ti(OH)Ti and (or) Ti(OH)Al. Hydroxyl groups coordinated to Ti atoms are involved in anchoring vanadium and tungsten oxide species. VOH (and probably WOH) groups are formed when this ternary oxide phase is dispersed on the TiO{sub x}/Al{sub 2}O{sub 3} support. {sup 51}V-NMR spectra indicated that tungsten oxide participates in the formation of the structure of the mixed oxide surface complexes. {sup 15}N-NMR spectroscopy of adsorbed N{sub 2}O permitted the detection of strong Lewis acid sites on these multicomponent supported oxide catalysts. The acid strength of (V{sub 2}O{sub 5}-WO{sub 3}) on TiO{sub x}/Al{sub 2}O{sub 3} catalysts turned out to be comparable to that of the TiO{sub x}/Al{sub 2}O{sub 3} support material. 39 refs., 9 figs., 2 tabs.
- OSTI ID:
- 273837
- Journal Information:
- Journal of Catalysis, Journal Name: Journal of Catalysis Journal Issue: 1 Vol. 156; ISSN 0021-9517; ISSN JCTLA5
- Country of Publication:
- United States
- Language:
- English
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