He Xing-Yue, Liu Yun-Zhu, Wang Si-Dun, Lan Xingwang, Li Xiao-Na, He Sheng-Gui
Key Laboratory of Chemical Biology of Hebei Province, College of Chemistry and Environmental Science, Hebei University, Baoding, Hebei, 071002, P.R. China.
State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
Dalton Trans. 2022 Aug 2;51(30):11491-11498. doi: 10.1039/d2dt01612e.
Noble metals dispersed on transition-metal carbides exhibit extraordinary activity in CO catalytic conversion and bimetallic carbides generated at the interface were proposed to contribute to the observed activity. Heteronuclear metal carbide clusters (HMCCs) that compositionally resemble the bimetallic carbides are suitable models to get a fundamental understanding of the reactivity of the related condensed-phase catalysts, while the reaction of HMCCs with CO has not been touched in the gas phase. Herein, benefiting from the newly designed double ion trap reactors, the reaction of laser-ablation generated and mass-selected RhTaC clusters with CO was studied. The experimental results identified that RhTaC can reduce four CO molecules consecutively and generate the product RhTaCO. The pivotal roles of Rh-Ta synergy and the C ligand in driving CO reduction were rationalized by theoretical calculations. The presence of an attached CO unit on the product RhTaCO was evidenced by the collision-induced dissociation experiment, providing a fundamental strategy to alleviate carbon deposition under a CO atmosphere at elevated temperatures.
负载于过渡金属碳化物上的贵金属在CO催化转化中表现出非凡的活性，有人提出在界面处生成的双金属碳化物有助于观察到的活性。组成上类似于双金属碳化物的异核金属碳化物簇（HMCCs）是从根本上理解相关凝聚相催化剂反应性的合适模型，而HMCCs与CO在气相中的反应尚未涉及。在此，受益于新设计的双离子阱反应器，研究了激光烧蚀产生并经质量选择的RhTaC簇与CO的反应。实验结果表明，RhTaC可以连续还原四个CO分子并生成产物RhTaCO。通过理论计算阐明了Rh-Ta协同作用和C配体在驱动CO还原中的关键作用。碰撞诱导解离实验证明了产物RhTaCO上存在附着的CO单元，这为在高温CO气氛下减轻碳沉积提供了一种基本策略。
