Study of Direct Synthesis of DMC from CO2 and Methanol on CeO2: Theoretical Calculation and Experiment

Rare earth metal oxides are known to have good catalytic effectiveness in the direct synthesis of dimethyl carbonate (DMC) from CO2 and methanol. In this work, we screened ceria (CeO2) catalysts by analyzing their capacity for CO2 adsorption. The effects of the crystal surface morphology and oxygen vacancy on the catalytic performance of the ceria catalyst were studied by using density functional theory (DFT). The results show that the (110) surface and higher oxygen vacancy content can better promote the synthesis of DMC and that the rod-shaped CeO2 catalyst has a better catalytic effect. The oxygen vacancy content on the catalyst was improved by freeze-drying and confirmed by thermogravimetric analysis, Raman spectroscopy, and electron paramagnetic resonance. The freeze-dried CeO2 (CeO2-FD) then showed a higher catalytic performance. The conversion rate of methanol and the yield of DMC were 33.95% and 584 mmol g-1cat, respectively, under mild conditions (140 degrees C and 1 MPa).