The Thermodynamic Properties and Homogeneous Catalysts for the Synthesis of Diphenyl Carbonate by Transesterification of Dimethyl Carbonate with Phenol

The Gibbs free energy of formation and entropy of liquid dimethyl carbonate(DMC) at 298.15K and 101.325kPa were estimated to be -472.3 kJ·mol -1 and 245.2 J·mol -1 ·K -1 respectively. The thermodynamic properties (Δ rH 0 m,Δ rS 0 m,Δ rG 0 m and equilibrium constant) of the reactions for the production of diphenyl carbonate(DPC) and anisole between DMC and phenol from 298K to 523K were calculated. These values indicated that the reaction of transesterification of DMC with phenol to DPC was endothermic and thermodynamically unfavorable. n Bu 2SnO, Ti(OC 4H 9) 4, AlCl 3 and ZnCl 2 were tested to catalyze the synthesis of DPC by transesterification of DMC with phenol. n Bu 2SnO had the highest catalytic activity among them. The optimum temperature was 453K for the synthesis of DPC. When the molar ratio of phenol to dimethyl carbonate was 4∶1, the yield and selectivity of DPC were 43.0% and 88.7% respectively using n Bu 2SnO as a catalyst.