Portal de Periódicos da CAPES

The interaction of vanadium pentoxide with titania (anatase): Part I. Effect on o-xylene oxidation to phthalic anhydride

1985; Elsevier BV; Volume: 15; Issue: 2 Linguagem: Inglês

10.1016/s0166-9834(00)81848-5

1873-3867

Israel E. Wachs, Ramzi Y. Saleh, Shirley S. Chan, Claudio C. Chersich,

Polyoxometalates: Synthesis and Applications

Two types of vanadia are present in active V205/TiO2(anatase) catalysts:a surface vanadia species coordinated to the TiO2 support and crystallites of V205. The surface vanadia is the active site in V20/TiO2(anatase)catalysts for the oxidation of o-xylene to phthalic anhydride. The TiO2(anatase)support must be covered by a complete monolayer of the surface vanadia species since exposed titania sites lead to complete combustion of the partial oxidation products. The surface vanadia species possess a higher activity and selectivity than crystalline V205 for this oxidation reaction. Moderate amounts of crystalline V905 do not significantly affect the catalytic performance of V205/TiO2(anatase) because of the low effective surface area and poor catalytic activity of this phase. The unique properties of the surface vanadia species are related to the vanadiatitania interaction.