Transesterification of glycerol with dimethyl carbonate for the synthesis of glycerol carbonate over Mg/Zr/Sr mixed oxide base catalysts

Abstract

A series of Mg/Zr/Sr based mixed oxide catalysts with varying molar ratios were prepared by a co-precipitation method. The X-ray diffraction and temperature programmed desorption of CO₂ were used to derive the characteristics of the catalysts. These catalysts were evaluated for the synthesis of glycerol carbonate by the transesterification of glycerol with dimethyl carbonate. The transesterification activity depended on the molar ratio of the Mg/Zr/Sr and the pre-treatment temperature of the catalysts. The catalysts basicity was influenced by the molar ratio of the mixed oxides and calcinations temperature. The catalyst with a Mg/Zr/Sr molar ratio of 3 : 1 : 1, calcined at 650 °C, showed the highest glycerol conversion and selectivity to glycerol carbonate. During this reaction, the formation of glycidol by the decarbonylation of glycerol carbonate was observed over the catalysts with a high basic strength. The reaction parameters also influence the glycerol conversion and selectivity to glycerol carbonate.