Exceptional Ozone Decomposition over δ-MnO2/AC under an Entire Humidity Environment

Ozone (O3) pollution is highly detrimental to human health and the ecosystem due to it being ubiquitous in ambient air and industrial processes. Catalytic decomposition is the most efficient technology for O3 elimination, while the moisture-induced low stability represents the major challenge for its practical applications. Here, activated carbon (AC) supported delta-MnO2 (Mn/AC-A) was facilely synthesized via mild redox in an oxidizing atmosphere to obtain exceptional O3 decomposition capacity. The optimal 5Mn/AC-A achieved nearly 100% of O3 decomposition at a high space velocity (1200 L g-1 h-1) and remained extremely stable under entire humidity conditions. The functionalized AC provided well designed protection sites to inhibit the accumulation of water on delta-MnO2. Density functional theory (DFT) calculations confirmed that the abundant oxygen vacancies and a low desorption energy of intermediate peroxide (O22-) can significantly boost O3 decomposition activity. Moreover, a kilo-scale 5Mn/AC-A with low cost (similar to 1.5 $/kg) was used for the O3 decomposition in practical applications, which could quickly decompose O3 pollution to a safety level below 100 mu g m-3. This work offers a simple strategy for the development of moisture-resistant and inexpensive catalysts and greatly promotes the practical application of ambient O3 elimination.

Automated summary

In this study, an activated carbon supported delta-MnO2 catalyst with exceptional ozone decomposition capacity was synthesized. It remained stable under high humidity conditions and was able to quickly decompose ozone pollution to below safety levels in practical applications.