Role of vanadia species in V2O5/TiO2 catalysts for toluene partial oxidation
The partial oxidn. of toluene over V2O5/TiO2 catalysts is a reaction of industrial interest. In spite of the detailed study of the nature of surface vanadia species, there is an evident lack of the information concerning their reactivity. The present work demonstrates an application of the transient response techniques in combination with in situ DRIFT and FT-Raman spectroscopy for the discrimination of the reactivity of different vanadia species. Catalysts consisting of 0.35-3.7 monolayers of vanadia on titania were studied. In anaerobic conditions, a conversion of toluene to benzaldehyde (BA) with a selectivity close to 100% was found. BA is formed mainly by nucleophilic (O2-) oxygen in isolated monomeric vanadia species, while electrophilic oxygen (O-) present in polymeric and bulk vanadia species is responsible for the formation of carbon oxides. An addn. of potassium was obsd. to increase the yield of BA. [on SciFinder (R)]
WOS:000166091201418
2000
COLL
284
Institute of Chemical Engineering,Swiss Federal Institute of Technology,Lausanne,Switz.
Journal; Meeting Abstract
written in English.