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 CeO_2- 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.