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- Title
Exploring the dynamic evolution of lattice oxygen on exsolved-Mn<sub>2</sub>O<sub>3</sub>@SmMn<sub>2</sub>O<sub>5</sub> interfaces for NO Oxidation.
- Authors
Wang, Xiyang; Yang, Qilei; Li, Xinbo; Li, Zhen; Gao, Chuan; Zhang, Hui; Chu, Xuefeng; Redshaw, Carl; Shi, Shucheng; Wu, Yimin A.; Ma, Yongliang; Peng, Yue; Li, Junhua; Feng, Shouhua
- Abstract
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
- Subjects
VALENCE fluctuations; X-ray photoelectron spectroscopy; REACTIVE oxygen species; ACTIVATION energy; ELECTRON density
- Publication
Nature Communications, 2024, Vol 15, Issue 1, p1
- ISSN
2041-1723
- Publication type
Article
- DOI
10.1038/s41467-024-51473-9