Chen Jiao-Jiao, Wang Si-Dun, Li Zi-Yu, Li Xiao-Na, He Sheng-Gui
State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
Beijing National Laboratory for Molecular Sciences and CAS Research/Education Center of Excellence in Molecular Sciences, Beijing 100190, China.
J Am Chem Soc. 2023 Aug 23;145(33):18658-18667. doi: 10.1021/jacs.3c06565. Epub 2023 Aug 12.
Catalytic conversion of toxic nitrogen oxide (NO) and carbon monoxide (CO) into nitrogen (N) and carbon dioxide (CO) is imperative under the weight of the increasingly stringent emission regulations, while a fundamental understanding of the nature of the active site to selectively drive N generation is elusive. Herein, in combination with state-of-the-art mass-spectrometric experiments and quantum-chemical calculations, we demonstrated that the rhodium-cerium oxide clusters RhCeO can catalytically drive NO reduction by CO and give rise to N and CO. This finding represents a sharp improvement in cluster science where NO is commonly produced in the rarely established examples of catalytic NO reduction mediated with gas-phase clusters. We demonstrated the importance of the unique chemical environment in the RhCeO cluster to guide the substantially improved N selectivity: a triatomic Lewis "acid-base-acid" Ce-Rh-Ce site is proposed to strongly adsorb two NO molecules as well as the NO intermediate that is attached on the Rh atom and can facilely dissociate to form N assisted by both Ce atoms.
在日益严格的排放法规的重压下，将有毒的氮氧化物（NO）和一氧化碳（CO）催化转化为氮气（N₂）和二氧化碳（CO₂）势在必行，而对于选择性驱动生成N₂的活性位点的本质的深入理解却难以捉摸。在此，结合最先进的质谱实验和量子化学计算，我们证明了铑-氧化铈簇RhCeO可以催化CO还原NO并生成N₂和CO₂。这一发现代表了簇科学的显著进步，在气相簇介导的催化NO还原这一鲜有实例中，通常会产生NO。我们证明了RhCeO簇中独特化学环境对于显著提高N₂选择性的重要性：提出了一个三原子路易斯“酸碱酸”Ce-Rh-Ce位点，它能强烈吸附两个NO分子以及附着在Rh原子上的NO中间体，该中间体在两个Ce原子的协助下能轻易解离形成N₂。
