Efficient Ozone Elimination Over MnO 2 via Double Moisture-Resistance Protection of Active Carbon and CeO 2 .

The widespread ozone (O 3 ) pollution is extremely hazardous to human health and ecosystems. Catalytic decomposition into O 2 is the most promising method to eliminate ambient O 3 , while the fast deactivation of catalysts under humid conditions remains the primary challenge for their application. Herein, we elaborately developed a splendidly active and stable Mn-based catalyst with double hydrophobic protection of active carbon (AC) and CeO 2 (CeMn@AC), which possessed abundant interfacial oxygen vacancies and excellent desorption of peroxide intermediates (O 2 2- ). Under extremely humid (RH = 90%) conditions and a high space velocity of 1200 L h -1 g -1 , the optimized CeMn@AC achieved nearly 100% O 3 conversion (140 h) at 5 ppm, showing unprecedented catalytic activity and moisture resistance toward O 3 decomposition. In situ DRIFTS and theory calculations confirmed that the exceptional moisture resistance of CeMn@AC was ascribed to the double protection effect of AC and CeO 2 , which cooperatively prevented the competitive adsorption of H 2 O molecules and their accumulation on the active sites of MnO 2 . AC provided a hydrophobic reaction environment, and CeO 2 further alleviated moisture deterioration of the MnO 2 particles exposed on the catalyst surface via the moisture-resistant oxygen vacancies of MnO 2 -CeO 2 crystal boundaries. This work offers a simple and efficient strategy for designing moisture-resistant materials and facilitates the practical application of the O 3 decomposition catalysts in various environments.