Preparation and catalytic property of MoO3/SiO2 for disproportionation of methyl phenyl carbonate to diphenyl carbonate

Abstract

MoO3/SiO2 were prepared by different methods and used as heterogeneous catalysts for the liquid-phase disproportionation of methyl phenyl carbonate (MPC) to diphenyl carbonate (DPC). The characterization of XRD, FT-IR and BET showed that the preparation methods remarkably affected the structural properties and catalytic activities of MoO3/SiO2. The MoO3/SiO2 prepared by a combined method of sol–gel and hydrothermal treatment (M-SGH) exhibited the highest catalytic activity, since high dispersion of MoO3, big specific surface area and large pores were obtained. Under the optimal conditions (200°C, 2h, using 0.9g catalyst with a MoO3 loading of 15wt%), the conversion of MPC reached 72.8% and the yield of DPC was 71.4%. Moreover, M-SGH showed excellent reusability and regeneration. After seven consecutive runs, the conversion of MPC decreased slightly from 72.8% to 56%. The formation of carbonate species on the catalyst surface was the main reason for the decrease of activity. The deactivated M-SGH could be facilely regenerated by calcination at 500°C in air, and the catalytic activity of regenerated M-SGH was completely recovered to the same with that of fresh.