CATALYTIC ACTIVITY OF VANADYL PHOSPHATE SUPPORTED ON TIO2 (ANATASE) AND SIO2 (SILICA)

Oxidation of n-butane was investigated on vanadyl phosphate (VP) prepared in the presence of titania (anatase) and silica as supports. In the case of silica, alpha-VOPO4 was synthesized with no sign of interaction between the silica surface and vanadium phosphate. On the contrary, titania was coated with amorphous VP (P/V = 1), preventing the crystallization of VOPO4 at least up to the VP content of 21%. n-Butane was completely converted into CO2 for the VP/TiO2 catalytic system. Upon impregnation with metal sulfates, maleic anhydride (MA) was produced with selectivities depending on the nature of the added metallic species, the best effect being observed with Fe2+ (V/Fe = 3). Selectivities to MA were influenced by the P/V ratio, with a maximum at P/V = 1.2.