Copper vanadate nanowires on g-C3N4 toward highly selective oxidation of methanol to dimethoxymethane

Abstract

The copper vanadate nanowires grown on g-C3N4 were fabricated with a simple impregnation approach. The organic-inorganic hybrid materials were characterized by various methods, involving XRD, SEM, TEM, FT-IR, XPS and N2 adsorption-desorption technique to identify their composition, structure and growing process. The selective oxidation of methanol was employed to assess the catalytic performance of the hybrid materials. The results revealed that the copper vanadate nanowires were mainly composed of Cu0.55V2O5 crystalline with mixed valence state of Cu+, Cu2+, V4+ and V5+, which were ascribed to in situ reduction during the preparation process. The hybrid composite was active and highly selective for methanol oxidation using molecular oxygen as oxidant with about 50% conversion of methanol and >99% selectivity to dimethoxymethane. The correlation between high activity and surface structure, composition of the catalyst, as well as the relationship between chemical potentials on catalyst surface and the reactivities, was analysed. The hybrid catalyst presented excellent operating lifetime and stability.