Exploring the dynamic evolution of lattice oxygen on exsolved-Mn2O3@SmMn2O5 interfaces for NO Oxidation

作者：Xiyang Wang, Qilei Yang, Xinbo Li, Zhen Li, Chuan Gao, Hui Zhang, Xuefeng Chu, Carl Redshaw, Shucheng Shi, Yimin A. Wu, Yongliang Ma, Yue Peng, Junhua Li, Shouhua Feng · 发表于：Nature Communications · 年份：2024 · DOI：10.1038/s41467-024-51473-9 · 被引用次数：45 · 研究领域：Catalytic Processes in Materials Science、Catalysis and Oxidation Reactions、Electrocatalysts for Energy Conversion

Lattice oxygen in metal oxides plays an important role in the reaction of diesel oxidation catalysts, but the atomic-level understanding of structural evolution during the catalytic process remains elusive. Here, we develop a Mn2O3/SmMn2O5 catalyst using a non-stoichiometric exsolution method to explore the roles of lattice oxygen in NO oxidation. The enhanced covalency of Mn–O bond and increased electron density at Mn3+ sites, induced by the interface between exsolved Mn2O3 and mullite, lead to the formation of highly active lattice oxygen adjacent to Mn3+ sites. Near-ambient pressure X-ray photoelectron and absorption spectroscopies show that the activated lattice oxygen enables reversible changes in Mn valence states and Mn-O bond covalency during redox cycles, reducing energy barriers for NO oxidation and promoting NO2 desorption via the cooperative Mars-van Krevelen mechanism. Therefore, the Mn2O3/SmMn2O5 exhibits higher NO oxidation activity and better resistance to hydrothermal aging compared to a commercial Pt/Al2O3 catalyst. This work reports on an exsolved Mn2O3/SmMn2O5 diesel oxidation catalyst competitive with current commercial materials in reactivity and hydrothermal aging resistance and further clarifies the catalytic mechanism for lattice oxygen as the reactive center