Glycerol carbonylation with CO2 to glycerol carbonate over CeO2 catalyst and the influence of CeO2 preparation methods and reaction parameters

The synthesis of glycerol carbonylation with CO2 to glycerol carbonate over CeO2 catalyst was investigated. CeO2 with different morphologies was prepared by traditional precipitation (TP), hydrothermal (TH) and citrate sol-gel (SG) methods, and the reaction of glycerol with CO2 was carried out in the presence of a dehydrating agent and solvent. The effect of preparation methods of CeO2 and reaction parameters on the activity and selectivity of the catalysts were examined. The structures, morphologies and surface properties of the catalysts were characterized by XRD, TEM, BET, CO2-TPD, H2-TPR, Raman and XPS. CeO2 exhibited high catalytic activity for the formation of glycerol carbonate under mild reaction conditions. The carbonylation of glycerol was influenced by the redox property of CeO2. The effects of different types of dehydrating agent and solvent were also studied. The dehydrating agent (2-cyanopyridine) and solvent (Dimethyl Formamide(DMF)) contributed to the increase of glycerol conversion and the yield of glycerol carbonate. The yield of glycerol carbonate could reach as high as 78.9%, and the catalysts could be easily regenerated by calcination at 400 °C for 5 h without loss of activity after 5 recycling times. The proper reaction conditions were 150 °C, 4 MPa and 5 h.