Chen Shuangqun, Cao Tong, Yan Wen, Zhao Ke, Guo Yalin, Wu Tiantian, Zhang Daliang, Ma Ming, Han Yu, Huang Jianfeng
State Key Laboratory of Coal Mine Disaster Dynamics and Control, Institute of Advanced Interdisciplinary Studies, School of Chemistry and Chemical Engineering, Chongqing University Chongqing 400044 P. R. China
School of Chemical Engineering and Technology, Xi'an Jiaotong University Xi'an 710049 P. R. China.
Chem Sci. 2025 May 2;16(23):10444-10453. doi: 10.1039/d5sc01998b. eCollection 2025 Jun 11.
Coordination modulation is a key strategy for enhancing the catalytic activity of single-atom catalysts (SACs) in CO electroreduction. However, achieving such modulation within the same framework by incorporating an array of heteroatoms with differing electronic properties remains unexplored, despite its potential for optimizing active sites. Here, we investigate unprecedentedly three Ni-based SACs (NNi-C, NNi-N, and NNi-O), where varying coordinating atoms (C, N, and O) modulate continuously the electronic structure to explore their effects on CO electroreduction. Compared to the NNi-N catalyst with classic Ni-N coordination, NNi-C demonstrates significantly enhanced CO conversion, achieving remarkably a near-unity Faradaic efficiency for CO (99.3%) at -0.7 V in the H-cell and a CO partial current density of 396.8 mA cm at -1.15 V in the flow cell, whereas NNi-O exhibits inferior performance. and computational investigations reveal that both C- and O-coordination enhance CO hydrogenation by elevating the Ni d-band center, thereby strengthening *COOH intermediate adsorption. However, the concurrent promotion of the hydrogen evolution reaction competes with CO reduction, ultimately leading to opposite effects on performance. This work provides atomic-level insights into CO electroreduction mechanisms and offers compelling strategies for improving SAC performance coordination modulation with heteroatoms.
配位调制是增强单原子催化剂（SACs）在CO电还原中催化活性的关键策略。然而，尽管通过引入一系列具有不同电子性质的杂原子在同一框架内实现这种调制具有优化活性位点的潜力，但尚未得到探索。在这里，我们前所未有的研究了三种镍基SACs（NNi-C、NNi-N和NNi-O），其中不同的配位原子（C、N和O）连续调节电子结构，以探索它们对CO电还原的影响。与具有经典Ni-N配位的NNi-N催化剂相比，NNi-C表现出显著增强的CO转化率，在H型电解池中-0.7 V时实现了近乎单位的CO法拉第效率（99.3%），在流动电解池中-1.15 V时CO分电流密度为396.8 mA cm，而NNi-O表现出较差的性能。计算研究表明，C配位和O配位都通过提高Ni d带中心来增强CO氢化，从而加强*COOH中间体的吸附。然而，析氢反应的同时促进与CO还原相互竞争，最终导致对性能的相反影响。这项工作提供了关于CO电还原机理的原子水平见解，并为通过与杂原子进行配位调制来提高SAC性能提供了引人注目的策略。
