Stable hydrogen evolution reaction at high current densities via designing the Ni single atoms and Ru nanoparticles linked by carbon bridges.

Yao, Rui; Sun, Kaian; Zhang, Kaiyang; Wu, Yun; Du, Yujie; Zhao, Qiang; Liu, Guang; Chen, Chen et al. · Nat Commun · 2024

basic_science · Level V

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Abstract

Continuous and effective hydrogen evolution under high current densities remains a challenge for water electrolysis owing to the rapid performance degradation under continuous large-current operation. In this study, theoretical calculations, operando Raman spectroscopy, and CO stripping experiments confirm that Ru nanocrystals have a high resistance against deactivation because of the synergistic adsorption of OH intermediates (OH<sub>ad</sub>) on the Ru and single atoms. Based on this conceptual model, we design the Ni single atoms modifying ultra-small Ru nanoparticle with defect carbon bridging structure (UP-RuNi<sub>SAs</sub>/C) via a unique unipolar pulse electrodeposition (UPED) strategy. As a result, the UP-RuNi<sub>SAs</sub>/C is found capable of running steadily for 100 h at 3 A cm<sup>-2</sup>, and shows a low overpotential of 9 mV at a current density of 10 mA cm<sup>-2</sup> under alkaline conditions. Moreover, the UP-RuNi<sub>SAs</sub>/C allows an anion exchange membrane (AEM) electrolyzer to operate stably at 1.95 V<sub>cell</sub> for 250 h at 1 A cm<sup>-2</sup>.