Creating water-resistant oxygen vacancies in δ-MnO2 by chlorine introduction for catalytic ozone decomposition at ambient temperature

To alleviate the negative impact of water vapor on ozone decomposition, we proposed a chlorine-doping strategy to create water-resistant oxygen vacancies in δ-MnO2. Comprehensive characterizations illustrated that abundant oxygen vacancies were generated by chlorine-doping, while fewer water and intermediates accumulated during ozone decomposition. Accordingly, chlorine-doped δ-MnO2 exhibited excellent activity for ozone decomposition, keeping 97.7% removal of 2000 ppm ozone after running for 40 h under the relative humidity of 65%. DFT calculations confirmed that chlorine introduction reduced the formation energy of oxygen vacancies and enhanced the strength of Mn-O bond. The compressed Mn-O bonds liberate oxygen vacancies from being occupied by water vapor and reaction intermediates. This work demonstrates the effectiveness of chlorine introduction in creating oxygen vacancies and enhancing its resistance to water vapor, which affords a new avenue to design high-performance catalysts for ozone elimination.