Effect of Facet on Oxygen Vacancy Properties in δ-MnO<sub>2</sub> for Stable and Efficient Catalytic Ozone Decomposition
Zhongyu Wang, Mingjia Zhang, Ting Li, Yan He, Shule Zhang, Qin Zhong
Abstract
Manganese oxides (MnO x ) serve as a classical catalytic material for ozone (O 3 ) decomposition, while the accumulation of the peroxide intermediate (*O 2 ) and water (H 2 O) significantly degrades its performance. In this study, the exposed ( 1 11) facet of δ-MnO 2 was prepared to modulate the properties and content of oxygen vacancies (Vo). Experimental and theoretical results indicate that δ-MnO 2 with the ( 1 11) facet possessed a lower Vo content compared to the thermodynamically stable (001) facet. Remarkably, despite the deficiency in Vo content, the rapid *O 2 desorption enables the catalyst to achieve superior performance, along with excellent stability. Additionally, the dynamic adsorption and reaction of H 2 O with O 3 significantly enhance the stability and water tolerance of the catalyst. The preferred Mn-0.2 maintained 95% O 3 conversion after 24 h of reaction under harsh conditions (WHSV = 900 L·g –1 ·h –1 and 35% RH). This work provides and validates new insights into strategies for mitigating the rate-determining step in an environmental catalytic reaction.