Ultrafine CeO2 Nanodots Embedded in Porous ZrO2 for Efficient and Sustainable Chlorine Recycle through Hydrochloric Acid Catalytic Oxidation

Abstract Ceria (CeO 2 ) has been regarded as one of the most promising industrial catalysts for hydrochloric acid (HCl) oxidation to replace RuO 2 ‐based catalysts. Thermal sintering and chlorination of CeO 2 limit its large‐scale application. In this work, ultrafine CeO 2 nanodots embedded in a porous ZrO 2 matrix (CeO 2 @ZrO 2 ) are successfully prepared by a spontaneous deposition method and evaluated in HCl catalytic oxidation for sustainable Cl 2 recycle. The physicochemical properties of CeO 2 @ZrO 2 catalysts are characterized by means of XRD, Raman, SEM, TEM, BET, XPS, H 2 ‐TPR and oxygen storage capacity (OSC). The results reveal that all CeO 2 @ZrO 2 catalysts display large specific surface area, pore volume, perfect low‐temperature reduction performance and oxygen storage‐release capacity. More importantly, the unique structure of the CeO 2 nanodots isolated by amorphous ZrO 2 improves the dispersion and inhibits the sintering of active sites. The optimized 40CeO 2 @ZrO 2 catalyst reveals superior activity (1.90 g Cl2 ⋅ g cat −1 ⋅ h −1 ) and good durability (100 h under 430 °C). Kinetic studies reveal that the adsorption of O 2 and HCl is competitive at the active sites, and the desorption of surface Cl is the rate‐determining step.