Surface properties of Cu/La2O3 and its catalytic performance in the synthesis of glycerol carbonate and monoacetin from glycerol and carbon dioxide.

Cu/La2O3 catalysts with different Cu loadings were prepared by impregnation method and employed in the synthesis of glycerol carbonate and monoacetin from glycerol and CO2 in the presence of CH3CN. The interface between Cu and La2O3 and the structure of catalysts were characterized by XRD, TEM, H2-TPR, CO2-TPD, N2O chemisorptions, UV-vis DSR and XPS. Cu/La2O3 exhibited high catalytic activity for the conversion of glycerol to glycerol carbonate and monoacetin under mild reaction conditions. The effect of reaction parameters on the carbonylation of glycerol was also studied. CH3CN can break the thermodynamic limit of the reaction of glycerol with CO2 to glycerol carbonate through its hydrolysis. Over 2.3%Cu/La2O3 catalyst, the conversion of glycerol and the selectivity to glycerol carbonate and monoacetin were 33.4%, 45.4% and 52.9%, respectively (150°C, 7.0 MPa, 12 h). The size effect of Cu nanoparticles and the basic property of the supports were also examined. The characterization results suggested that the Cu sizes and basic sites on Cu/La2O3 had significant effect on the conversion and selectivity in the carbonylation of glycerol.