Heterogeneous Transesterification of Dimethyl Carbonate and Phenol to Diphenyl Carbonate over Vanadium Pentoxide Microstructures

摘要

Vanadium pentoxide (V2O5) microstructures were synthesized by calcining acidtreated NH4VO3 at 773 K in air, which were used as heterogeneous catalysts for the synthesis of diphenyl carbonate (DPC) by the transesterification of dimethyl carbonate (DMC) with phenol. The effects of the types of acid and the transesterification reaction time on catalytic activities were investigated. Under the conditions of reaction temperature of 453 K, a catalyst amount of 0.2% (molar ratio to phenol), molar ratio of DMC/phenol of 1:2 and a reaction time of 13 h, the maximum conversion of DMC and total yields of methyl phenyl carbonate (MPC) and DPC were 23.23 and 23.44%, respectively. The selectivity to the transesterification was nearly 100%. The plausible mechanism of the transesterification catalyzed by the V2O5 microstructures was also probed preliminarily. X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM) characteristics of the catalyst samples had been recorded.