Nonmetallic Modified Atomically Precise Octagold Nanoclusters for Electrocatalytic Nitrate Reduction to Ammonia

作者：Xiaojuan Zhu, Wei‐Dan Si, Kaiyu Qu, Leyang Song, Jing Wang, Yushuang Gong, Di Sun, Xiang Liu, An‐Liang Wang · 发表于：Journal of the American Chemical Society · 年份：2025 · DOI：10.1021/jacs.5c15788 · 被引用次数：21 · 研究领域：Ammonia Synthesis and Nitrogen Reduction、Advanced Photocatalysis Techniques、Nanocluster Synthesis and Applications

Atomically precise metal nanoclusters (NCs) with metal cores functionalized by nonmetallic elements hold great promise for electrocatalytic NO 3 – reduction reaction (NO 3 RR). However, elucidating structural evolution during catalysis and precisely identifying the active sites remain formidable challenges. Herein, we have synthesized [Au 8 S 2 (dppm) 4 ] 2+ and [Au 8 Se 2 (dppm) 4 ] 2+ (dppm: Ph 2 PCH 2 PPh 2 ) NCs with Au cores modified by S or Se atoms and subjected them to electrochemical pre-activation. Comprehensive experiments reveal that pre-activation leads to the removal of one dppm ligand from both NCs, thereby exposing metallic Au sites. As NO 3 RR catalysts, the activated [Au 8 S 2 (dppm) 4 ] 2+ achieves an NH 3 yield rate of 1108.47 mg h –1 mg Au –1 and a Faradaic efficiency of 98.34%, significantly surpassing [Au 8 Se 2 (dppm) 4 ] 2+, most reported NCs, and conventional nanocatalysts. Mechanistic studies unveil that the exposed metallic Au sites after pre-activation serve as the primary catalytic center. Furthermore, the introduction of S atoms into the Au core induces a more positive surface potential, upshifts the Au-d band center, enhances NO 3 – adsorption, and strengthens the balance between the generation and consumption of active hydrogen, collectively boosting the NO 3 RR performance. This work not only provides definitive experimental evidence for structural evolution and active-site identification in atomically precise NCs under electrolysis, but also...