Abstract

Non-Pt or low-Pt catalysts capable for stable generation of hydrogen via water electrolysis at an industrial level of current density are highly demanded. Construction of strong metal-support connection is beneficial to improve the performance stability of electrocatalysts. Here we employed highly defective N-doped carbon nanotubes (d-N-CNT) as the support to achieve uniform and firm anchoring of Ru clusters (~ 1.9 nm) via a thermal-shock strategy. The as-prepared Ru/d-N-CNT catalyst shows excellent catalytic activity for hydrogen evolution reaction (HER) in alkaline media and requires an overpotential (η) of 12 mV at 10 mA·cm⁻² and 116 mV at 200 mA·cm⁻² with a Ru loading of 0.025 mg·cm⁻². Impressively, Ru/d-N-CNT presents robust stability for HER at both low current density (stable for at least 1000 h at 10 mA·cm⁻²) and the industrial level of current density (stable for at least 100 h at 1000 mA·cm⁻²), remarkably outperforming commercial Pt/C and Ru/C. The highly defective nature of the N-CNT support endowed the as-prepared Ru/d-N-CNT catalyst with strong metal–support adhesion that efficiently suppressed agglomeration as well as obscission of Ru clusters. Meanwhile, the rich defects increased the surface energy of the N-CNT support and resulted in improved hydrophilicity as evidenced by the liquid contact angle measurement and the bubble evolution process, which also played an important role in stabilizing the HER performance especially at large current density.

中文翻译：

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通过热冲击策略将 Ru 簇锚定到高度缺陷的 N 掺杂碳纳米管上，以实现稳定的工业析氢

摘要

人们非常需要能够在工业水平的电流密度下通过水电解稳定产生氢气的非铂或低铂催化剂。构建强金属-载体连接有利于提高电催化剂的性能稳定性。在这里，我们采用高度缺陷的 N 掺杂碳纳米管 (dN-CNT) 作为支撑，通过热冲击策略实现 Ru 簇 (~ 1.9 nm) 的均匀和牢固锚定。所制备的Ru/dN-CNT催化剂在碱性介质中对析氢反应（HER）表现出优异的催化活性，并且在10 mA·cm ^-2下需要12 mV的过电势（η）和在200 mA·cm -2 下116 mV的过电势（η ^{） 2}，Ru负载量为0.025mg·cm ^-2。^{令人印象深刻的是，Ru/dN-CNT 在低电流密度（在 10 mA·cm -2}下稳定至少 1000 小时）和工业水平电流密度（在 1000 mA·cm 下稳定至少 100 小时）均表现出强大的 HER 稳定性。 cm ^-2），明显优于商用 Pt/C 和 Ru/C。N-CNT 载体的高度缺陷性质赋予所制备的 Ru/dN-CNT 催化剂强大的金属-载体粘附力，有效抑制 Ru 团簇的团聚和脱落。同时，丰富的缺陷增加了 N-CNT 载体的表面能，并导致亲水性提高，如液体接触角测量和气泡演化过程所证明的那样，这对于稳定 HER 性能特别是在大电流密度下也发挥了重要作用。