Performance, structure, and mechanism of CeO2 in HCl oxidation to Cl2

► CeO2 is a cost-effective alternative to RuO2 for catalyzed Cl2 production. ► HCl oxidation activity of CeO2 is linked to oxygen vacancies. ► Calcination temperature key to maximize activity and structural stability. ► The chlorination extent of CeO2 depends on the feed O2/HCl ratio and is highly dynamics. ► Catalyst re-oxidation is rate-determining step.