The development of an efficient electrocatalyst toward the hydrogen evolution reaction (HER) is of significant importance in transforming renewable electricity to pure and clean hydrogen by water splitting. However, the construction of an active electrocatalyst with multiple sites that can promote the dissociation of water molecules still remains a great challenge. Herein, a partial‐single‐atom, partial‐nanoparticle composite consisting of nanosized ruthenium (Ru) nanoparticles (NPs) and individual Ru atoms as an energy‐efficient HER catalyst in alkaline medium is reported. The formation of this unique composite mainly results from the dispersion of Ru NPs to small‐size NPs and single atoms (SAs) on the Fe/N codoped carbon (Fe–N–C) substrate due to the thermodynamic stability. The optimal catalyst exhibits an outstanding HER activity with an ultralow overpotential (9 mV) at 10 mA cm⁻² (η₁₀), a high turnover frequency (8.9 H₂ s⁻¹ at 50 mV overpotential), and nearly 100% Faraday efficiency, outperforming the state‐of‐the‐art commercial Pt/C and other reported HER electrocatalysts in alkaline condition. Both experimental and theoretical calculations reveal that the coexistence of Ru NPs and SAs can improve the hydride coupling and water dissociation kinetics, thus synergistically enhancing alkaline hydrogen evolution performance.

中文翻译：

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部分单原子、部分纳米粒子复合材料增强水解离以析氢

开发一种高效的析氢反应（HER）电催化剂对于通过水分解将可再生电力转化为纯净的氢气具有重要意义。然而，构建具有多个位点、可促进水分子解离的活性电催化剂仍然是一个巨大的挑战。本文报道了一种由纳米级钌 (Ru) 纳米颗粒 (NP) 和单个 Ru 原子组成的部分单原子、部分纳米粒子复合材料，作为碱性介质中的节能 HER 催化剂。这种独特复合材料的形成主要是由于Ru NPs由于热力学稳定性而在Fe/N共掺杂碳(Fe-N-C)基底上分散成小尺寸NPs和单原子(SA)所致。最佳催化剂表现出出色的 HER 活性，在 10 mA cm ^-2 ( η ₁₀ ) 下具有超低过电势 (9 mV)、高周转频率 (50 mV 过电势下为 8.9 H ₂ s ^-1 ) 和接近 100% 的法拉第效率，在碱性条件下优于最先进的商用 Pt/C 和其他报道的 HER 电催化剂。实验和理论计算表明，Ru NPs和SAs的共存可以改善氢化物偶联和水解离动力学，从而协同增强碱性析氢性能。