CeO2 nanorods with bifunctional oxygen vacancies for promoting low-pressure photothermocatalytic CO2 conversion with CH3OH to dimethyl carbonate

Abstract

The direct synthesis of dimethyl carbonate (DMC) from CO2 and methanol is a kind of highly-attractive route for CO2 conversion to high value-added chemicals. However, a key core problem is how to more effectively activate CO2. Here, we adopt simple template-free hydrothermal method to prepare CeO2 nanorods with oxygen vacancies and introduce light energy into the thermal catalysis system for promoting low-pressure photothermalcatalytic CO2 with methanol direct conversion to DMC. The SEM, HRTEM, XRD, XPS, N2 adsorption-desorption isotherm, CO2-TPD, EPR, Raman, photoluminescence spectra and UV-Vis-IR DRS characterizations are carried out to analyze the microscopical properties including the crystal phases, chemical states, structural features, optical properties for building up the intrinsic relationship with macroscopic performance. Our findings reveal that oxygen vacancies can not only act as photo-produced charge trapping center to prevent the recombination of photoinduced electrons and holes, but also promote CO2 adsorption and activation abilities through Lewis acid-base interaction. Finally, the detailed action mechanism for photothermalcatalytic CO2 conversion with methanol to DMC is proposed. This work should provide new ideas and insights for achieving the CO2 conversion into high value-added long-chain chemicals.