G. Bond
Apr 1, 1989
Citations
0
Influential Citations
47
Citations
Journal
Journal of Catalysis
Abstract
A mechanism is proposed for the selective oxidation of o-xylene to phthalic anhydride catalysed by V2O5TiO2. The chief catalytic species is identified as an oxohydroxy-vanadium group forming a monolayer on the TiO2 (anatase) surface, and possible unit reactions involving this and related groups with o-xylene and with organic species formed from it are presented: these account for the formation of intermediate products (o-tolualdehyde, phthalide, etc.) as well as of phthalic anhydride itself. The five-membered ring products (phthalide, phthalic anhydride) may arise by dehydration of noncyclic precursors. The unique catalytic properties of the V2O5TiO2 system arise from the conjunction in the same active centre of a reducible VO bond and an acidic hydroxyl group.