CREATION, CHARACTERIZATION AND PERFORMANCE OF VANADYL ACTIVE-SITES INMICROPOROUS AND MESOPOROUS SILICA-BASED CATALYSTS FOR THE SELECTIVE OXIDATION OF HYDROCARBONS

We here describe how to design vanadium-centred active sites at the in ner surfaces of both well defined microporous and well defined mesopor ous siliceous hosts. Each type of vanadia-silica catalyst has been ext ensively characterised (in regard to surface area, pore size and hydro phobicity) and X-ray absorption spectroscopy establishes the active si te for these conversions to be a vanadyl group. These centres are cata lytically active under mild conditions for both the epoxidation of a t ypical alkene and the selective oxidation of a typical alkane. Placing methyl groups in the vicinity of this active site significantly enhan ces the catalytic performance towards epoxidation.