Fourier-transform infrared investigation of intermediates in the oxidation of toluene on V2O5/TiO2

Abstract

The adsorption and oxidation of toluene on V–Ti oxide prepared by the gas-phase method (2.1 to 5.6 wt%) has been studied by F.t.i.r. spectroscopy as well as the microcatalytic method. It is found that toluene is bonded as a π-complex to the vanadium ion. The CH₃ groups of the π-complex are dehydrogenated by the VO species to form benzyl species at room temperature. The formation of aldehyde-like intermediate before the oxidation of benzyl species to benzoate has been confirmed. The reactivity of surface VO species of V–Ti oxide prepared by a gas-phase method is greater than that of the impregnation catalyst.