Dynamic Tuning of Oxygen Vacancies in Mn–Ce Catalysts via the Electron Complementary Effect for Enhanced Reduction of NO by CO

Developing efficient nonprecious metal catalysts for NO reduction using CO under O₂-containing conditions has always been the focus of attention. In this study, the asymmetric Mn-O_v-Ce structure was constructed on the Mn-Ce catalyst via a coprecipitation strategy. The optimized Mn_0.2Ce_0.8O₂ catalyst exhibited superior catalytic performance, achieving 90% NO conversion and 95% N₂ selectivity at 260 °C under 5% O₂. Characterizations and theoretical calculations revealed that the asymmetric Mn-O_v-Ce configuration promoted electron delivery between Mn and neighboring Ce, facilitating the generation of dynamic O_v. Furthermore, in situ DRIFTS and DFT calculations demonstrated that the incorporated Mn was favorable to a faster consumption of intermediates and the dynamic replenishment of O_v on the CeO₂ surface, thus promoting the catalytic performance. This study provides an efficient scheme for designing high-efficiency performance Ce-based catalysts by tuning the electronic structure of CeO₂ for NO reduction by CO under the O₂-containing conditions.