Effect of Exposed Facets and Oxidation State of CeO2 Nanoparticles on CO2 Adsorption and Desorption.

CeO2 nanoparticles exhibit potential as solid adsorbents for carbon dioxide (CO2) capture and storage (CCS), offering precise control over various facets and enhancing their efficiency. This study investigated the adsorption and desorption behaviors of two types of CeO2 nanoparticles: cubic CeO2 with primarily {001} facets and polyhedral CeO2 with mainly {111} facets. The results showed that despite polyhedral CeO2's lower quantity, it demonstrated successful adsorption-desorption cycles in both oxidized and reduced states. However, reduced CeO2-x exhibited a higher adsorption capacity but displayed irreversible adsorption-desorption cycles. Reversible adsorption occurred through weak bond formation with CO2, while cubic CeO2 with a high oxygen vacancy concentration exhibited irreversible adsorption due to strong bond formation. These insights contribute significantly to understanding CeO2 nanoparticle characteristics and their impact on the CO2 adsorption and desorption processes, aiding in the development of advanced CCS techniques.