Highly efficient selective oxidation of toluene to benzaldehyde over Cu–V oxides supported on amorphous SiO2

Abstract

Selective oxidation of toluene into high-value-added benzaldehyde is meaningful and challenging. In this study, a series of amorphous SiO₂-supported bimetallic Cu–V oxides were prepared, showing excellent catalytic activity for the oxidation of toluene compared to their mono-metallic oxide catalysts. It was found that the best catalytic performance was observed with benzaldehyde selectivity of 87.3% and toluene conversion of 84.1% under mild reaction conditions, using peroxydisulfate (PDS) as the oxidant. The main by-product was benzoic acid. A strong synergistic interaction between Cu and V species has been revealed via a series of characterization techniques, which can boost the catalytic performance. This work may provide a green and cheap process for the selective oxidation of toluene to benzaldehyde.