Synthesis of dimethyl carbonate from carbon dioxide, propylene epoxide and methanol

Dimethyl carbonate (DMC) was synthesized from carbon dioxide, propylene epoxide (PO) and methanol. The catalytic performance of K2CO3, KI, rare earth oxides including CeO2, Y2O3, La2O3 and Yb2O3 was investigated. Acceptable conversion of PO but poor selectivity to DMC was obtained using K2CO3 or KI as the sole catalyst compared to that obtained in the presence of rare earth oxides. Significant improvement in the selectivity to DMC was obtained catalyzed by co-catalyst composed of K2CO3 and Yb2O3, and 42.4% selectivity to DMC, which is higher than that obtained using K2CO3 or Yb2O3 as the sole catalyst under the identical conditions, was obtained. The influence of the amount of PO was also investigated, and the results showed that the conversion of PO is dependent on its amount.