A study of active sites for alkene and alkane oxidation over Mo and V mixed oxide catalysts using 18O tracer and Raman spectroscopy

Abstract

The oxygen ions of MoO3, V2O5, β-VOPO4, α-Mg2V2O7, β-CoMoO4and α-Bi2Mo3O12were exchanged with 18O via a reduction–oxidation method and the catalytic oxidation of alkene or alkane using 18O2. The Raman bands of the catalysts shifted to lower frequencies by the exchange with 18O tracer. With MoO3, V2O5, β-VOPO4and α-Mg2V2O7, the weak oxygen bonds were active to exchange, i.e., to be active for the oxygen insertion and oxidation reactions, but the strong bonds were less active. The results of exchange features on α-Bi2Mo3O12catalyst indicate that some sets of two lattice oxygen ions in a twin tetrahedra seem to be good for fitting and bonding with allyl intermediates.