Synthesis of glycerol carbonate from glycerol and diethyl carbonate over CeO2-CdO catalyst: The role of Ce4+ doped into CdO lattice

A series of Ce 1- x Cd x O mixed oxide catalysts prepared by co-precipitation method were tested for synthesis of glycerol carbonate (GC) from glycerol and diethyl carbonate (DEC). The microstructural and physicochemical properties of the bimetal catalysts were characterized by XRD, SEM, TEM, XPS, CO 2 -TPD, N 2 -adsorption, TG-DSC and 1 H NMR. The results show that the spherical particles of CdO were uniformly dispersed on the surface of lamellar CeO 2 . Besides, a noticeable increase was observed in the moderate basic sites concentration, because more oxygen atoms were adsorbed on the bimetal sample surface which was attributed to Ce 4+ doped into CdO lattice. The Ce 0.7 Cd 0.3 O sample annealed at 500 °C was observed with the highest catalytic activity. 96.84% of glycerol conversion and 100% selectivity to GC were obtained over this catalyst under the optimized conditions (5 wt.% catalyst of glycerol, 90 °C, 180 min, glycerol/DEC molar ratio of 1:3). Besides, it was found that the conversion of glycerol carbonate was synergistically accelerated by the moderate and strong basic sites.