Influence of additives on the oxidative carbonylation of methanol to synthesis of dimethyl carbonate over copper catalysts

Influence of additives on the oxidative carbonylation of methanol to synthesis of dimethyl carbonate over copper catalysts Chen Zhensong, Liu Dinghua, Liu Xiaoqin (State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009, China) Abstract: Hydrolytic and catalytic activity of copper catalyst and several additives (water absorbents and solvents) were investigated in the oxidative carbonylation of methanol to synthesis of dimethyl carbonate (DMC). The results showed that synthesis of dimethyl carbonate from methanol can be promoted a little by the introduction of the alkalescence water absorbent K₂CO₃ and the high boiling polar aprotic solvent N,N-dimethylacetamide. Under the reaction conditions of 100-110°C of temperature, pressure of 3.5 MPa, reaction time of 4 h, Cu_xBr_nL_m catalyst concentration of 0.15 g/mL and CuBr₂ concentration of 0.075 g/mL, the methanol conversion could exceed 48.5% and the DMC selectivity was about 92.5% when the concentraion of alkalescence water absorbent K₂CO₃ was 0.001 g/mL and solvent N, N-dimethylacetamide was 0.3 volume ratio to methanol, which may be useful to practical production.