Efficient Ozone Elimination Over MnO2 via Double Moisture-Resistance Protection of Active Carbon and CeO2

Abstract

The widespread ozone (O₃) pollution is extremely hazardous to human health and ecosystems. Catalytic decomposition into O₂ is the most promising method to eliminate ambient O₃, 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 CeO₂ (CeMn@AC), which possessed abundant interfacial oxygen vacancies and excellent desorption of peroxide intermediates (O₂^2–). 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% O₃ conversion (140 h) at 5 ppm, showing unprecedented catalytic activity and moisture resistance toward O₃ 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 CeO₂, which cooperatively prevented the competitive adsorption of H₂O molecules and their accumulation on the active sites of MnO₂. AC provided a hydrophobic reaction environment, and CeO₂ further alleviated moisture deterioration of the MnO₂ particles exposed on the catalyst surface via the moisture-resistant oxygen vacancies of MnO₂–CeO₂ crystal boundaries. This work offers a simple and efficient strategy for designing moisture-resistant materials and facilitates the practical application of the O₃ decomposition catalysts in various environments.