Catalytic synthesis of glycerol carbonate from biomass-based glycerol and dimethyl carbonate over Li-La2O3 catalysts

The trans-esterification of glycerol and dimethyl carbonate (DMC) for the synthesis of glycerol carbonate was investigated over a series of Li-La 2 O 3 catalysts with different Li contents under mild reaction conditions. Li-La 2 O 3 catalysts were prepared by simple precipitation and impregnation methods, and characterized using ICP, XRD, BET, XPS, CO 2 -TPD and TEM techniques. It was found that the basicity of La 2 O 3 was obviously changed and the interaction between Li and La 2 O 3 occurred after doping Li component, and the catalytic activity of Li-La 2 O 3 was highly relevant to the strength and content of basic sites on the catalysts. Li doping influenced the crystal phase growth of La 2 O 3 , and also changed the exposed crystal planes of the Li-La 2 O 3 catalysts. The highest catalytic performance was obtained over 3.50Li-La 2 O 3 catalyst calcined at 600 °C for 5 h. The glycerol conversion of 94.4% and glycerol carbonate selectivity of 92.1% were obtained over this catalyst under the proper reaction conditions of 85 °C, 3 h, and the molar ratio of glycerol and DMC being 1/3 with using 0.1 g 3.50Li-La 2 O 3 catalyst.