Structure of vanadium oxides on ZrO2 and the oxidation of butene
Abstract
The oxidation of butene on V–Zr oxides prepared by the gas-phase and the impregnation method has been studied by F.t.i.r. spectroscopy as well as the microcatalytic method. V–Zr catalysts above 6.0 wt % vanadium loading show almost constant activity. V–Zr catalysts at low vanadium loadings show high selectivities to furan and buta -1.3-diene, while high vanadium loading catalysts show high selectivities to acetaldehyde and acetic acid. The formation of a dihydrofuran-like intermediate before the formation of furan has been proposed. The oxyhydrative scission mechanism is proposed in the formation of acetaldehyde and acetic acid. This formation is attributed to the presence of Brønsted acidity.