Synthesis of dimethyl carbonate from CO2 and methanol over CeO2 nanoparticles/Co3O4 nanosheets

Abstract

The reaction of methanol and CO2 is an ideal route for the utilization of CO2 resources and the synthesis of dimethyl carbonate (DMC), which is an important fuel and fuel-additive. In this work, we developed a catalyst of CeO2 nanoparticles (CeO2 NPs) loaded on Co3O4 nanosheets (Co3O4 NSs) with the Ce/Co molar ratio of 3/7 (Ce3-NPs/Co7-NSs) which could efficiently catalyze the reaction. The formation activity and the yield of DMC reached 16.8 mmol·gcat-1·h−1 and 47.2 % (based on methanol), surpassing most reported catalysts, especially at a relatively low temperature of 120 ℃. Characterization results indicated that the Co3O4 NSs could enhance the amounts of oxygen vacancies and CO2 adsorption but reduce methanol adsorption. The adsorption equilibrium between methanol and CO2 is crucial for the titled reaction, and the in-situ IR spectra confirmed that the catalyst could simultaneously activate CO2 and methanol and the reaction involves a Langmuir-Hinshelwood (LH) mechanism. The present strategy for constructing a catalyst of CeO2 nanoparticles loaded on Co3O4 nanosheets provides an efficient catalyst for the DMC synthesis from CO2 and methanol and offers an important reference in building other catalysts with adjustable adsorption capacities of CO2 and methanol.