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.