The design of efficient and cost-effective platinum-based catalysts for the hydrogen evolution reaction (HER) is critical for energy sustainability. Herein, we report high catalytic activity toward HER on the edges of platinum nanoclusters (NCs) supported on single-layer molybdenum disulfide and provide a direct link between ab initio calculations and electrochemical experiments. We determine the active catalytic sites using a cluster expansion method in conjunction with an ab initio thermodynamic approach and show that the system is thermodynamically active at HER reversible potential under electrochemical conditions. We also show that the preferred HER mechanism is the Volmer–Tafel pathway with the Volmer reaction as the rate-determining step. Using a Butler–Volmer kinetic model to simulate a linear sweep voltammogram, we obtain an exchange current density of 10^–3–10^–2 A/cm², which is in the same order as those measured for Pt(111) and supported Pt NCs. Importantly, we show that, contrary to expectations, the enhanced HER mechanism is only attributable to the edges of the supported Pt NCs but not due to metal–support interactions. Our findings are general and applicable to NCs with different sizes and shapes on various supports as well as to different catalytic reactions.

中文翻译：

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MoS ₂负载的铂纳米团簇边缘的高能级，通过团簇膨胀和电化学建模

设计高效且具有成本效益的用于氢气析出反应（HER）的铂基催化剂对能源的可持续性至关重要。本文中，我们报道了在单层二硫化钼上负载的铂纳米团簇（NC）边缘对HER的高催化活性，并提供了从头算和电化学实验之间的直接联系。我们使用簇扩展方法结合从头算热力学方法确定了活性催化位，并表明该系统在电化学条件下在HER可逆电势下具有热力学活性。我们还表明，首选的HER机制是Volmer-Tafel途径，其中Volmer反应是决定速率的步骤。使用Butler–Volmer动力学模型来模拟线性扫描伏安图，^–3 –10 ^–2 A / cm ²，其顺序与对Pt（111）和支持的Pt NC测量的顺序相同。重要的是，我们表明，与预期相反，增强的HER机制仅归因于受支持的Pt NC的边缘，而不归因于金属与载体的相互作用。我们的发现是普遍的，适用于在各种载体上具有不同大小和形状的NC以及不同的催化反应。