Enhanced CO2 Adsorption on CeO2/SBA‐15: The Key Role of Oxygen Vacancies

This study investigates the role of oxygen vacancies in the CO 2 adsorption and desorption dynamics of SBA‐15:CeO 2 nanocomposites synthesized by direct (DS) and postsynthesis (PS) methods. Physicochemical analyses reveal that the DS method increases the concentration of oxygen vacancies and structural defects within the CeO 2 framework, which significantly boosts CO 2 adsorption capacity and strengthens the gas‐surface interactions. Among the materials, S_Ce4.a demonstrates the highest adsorption capacity, reaching 29.4 mg g − 1 at 25 °C and 10.7 mg g −1 at 70 °C. These results indicate a physisorption mechanism governed by both thermal conditions and oxygen vacancies. Furthermore, S_Ce4.a and S_Ce10.a. exhibit remarkable stability over 20 adsorption–desorption cycles. The findings suggest that a lower cerium oxide content provides more accessible adsorption sites, making these materials promising candidates for high‐performance. Overall, this work highlights synergistic interplay between oxygen vacancies and mesoporous structures, paving the way for the rational design of advanced materials for CO 2 capture technologies.