Ligand-protected copper nanoclusters (Cu NCs) with atomic precision have emerged rapidly due to their fascinating structural architectures and versatile catalytic properties, making them ideal for investigating structure–activity relationships. Despite their potential, challenges such as stability issues and limited structural diversity have restricted deeper exploration. In this study, three distinct Cu NCs were synthesized using a one-pot reduction strategy by carefully modifying reaction conditions. Intriguingly, the same p-toluenethiol ligand produced two different geometries, while varying ligand with m-aminobenzethiol—yielded clusters with similar geometric architectures. These NCs were evaluated for electrocatalytic CO2 reduction, uncovering diverse catalytic activities and product selectivity. Experimental and theoretical analyses revealed that the interplay between the core structure confinement and surface ligand environment governs their catalytic behavior. Specifically, the Cu11 NC with p-toluenethiol ligand exhibited selectivity toward HCOOH production (FEHCOOH~45% at -1.2 V vs. RHE), whereas substituting p-toluenethiol with m-aminobenzethiol shifted the selectivity to the competitive side reaction (FEH2~82% at -1.2 V vs. RHE). Conversely, altering the geometry of Cu18 NC while retaining the p-toluenethiol ligand decreased such selectivity (FEHCOOH~35% at -1.2 V vs. RHE). These findings highlight the tunability of Cu NCs for tailored catalytic applications through precise control of their structure and surface chemistry.

中文翻译：

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破译 Cu 纳米团簇中的电催化活性：结构限制与配体环境之间的相互作用


由于其迷人的结构结构和多功能的催化特性，具有原子精度的配体保护铜纳米团簇 （Cu NCs） 迅速出现，使其成为研究构效关系的理想选择。尽管它们具有潜力，但稳定性问题和有限的结构多样性等挑战限制了更深入的勘探。在这项研究中，通过仔细修改反应条件，使用一锅还原策略合成了三种不同的 Cu NC。有趣的是，相同的对甲苯硫醇配体产生了两种不同的几何形状，而与间氨基苯乙基不同的配体则产生了具有相似几何结构的簇。对这些 NC 进行了电催化 CO2 还原评估，揭示了不同的催化活性和产物选择性。实验和理论分析表明，核心结构限制和表面配体环境之间的相互作用控制着它们的催化行为。具体来说，具有对甲苯硫醇配体的 Cu11 NC 对 HCOOH 的产生表现出选择性（FEHCOOH~45%，-1.2 V vs. RHE），而用间氨基苯乙醇取代对甲苯硫醇则选择性转移到竞争性反应（FEH2~82%，-1.2 V vs. RHE）。相反，改变 Cu18 NC 的几何形状同时保留对甲苯硫醇配体会降低这种选择性（-1.2 V 与 RHE 时 FEHCOOH~35%）。这些发现突出了 Cu NC 通过精确控制其结构和表面化学性质，为定制催化应用提供可调性。