Manipulation of Oxygen Vacancy on a CeO2 Catalyst for the Carbonylation of Glycerol with CO2

Cerium dioxide (CeO2) with different morphologies was synthesized via a hydrothermal method and applied to the carbonylation of glycerol with CO2. Subsequent characterization through H2-TPR and catalytic activity tests demonstrated that CeO2 nanorods exhibited the highest oxygen storage/release capacity as well as enhanced catalytic performance compared to other morphologies. CeO2 nanorods were thus further modified through hydrogen reduction at varying temperatures, aiming to tune the density of the oxygen vacancies. Characterization via BET, NH3-TPD, CO2-TPD, XPS, and ESR indicated that variations in morphology and reduction temperature influenced the microstructural characteristics and the strength of the acid–base sites of the catalysts. Notably, hydrogen reduction created more oxygen vacancies in the CeO2 nanorods, with the concentration of these vacancies increasing with higher reduction temperatures. Furthermore, the catalytic activity of CeO2 in glycerol carbonylation with CO2 showed a positive correlation with the concentration of oxygen vacancies. Optimizing CeO2 catalysts can enhance its performance in activating CO2, providing new ideas for industrial CO2 resource utilization and carbon capture technology development.