Isolated Ni Atoms Dispersed on Ru Nanosheets: High-Performance Electrocatalysts toward Hydrogen Oxidation Reaction.

Mao, Junjie; He, Chun-Ting; Pei, Jiajing; Liu, Yan; Li, Jun; Chen, Wenxing; He, Dongsheng; Wang, Dingsheng et al. · Nano Lett · 2020

basic_science · Level V

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Abstract

Designing low-cost, high-efficiency, platinum-free electrocatalysts for the hydrogen oxidation reaction (HOR) in an alkaline electrolyte is of great importance for the development of anion exchange membrane fuel cells. Herein, we report a novel HOR catalyst, RuNi1, in which Ni is atomically dispersed on the Ru nanocrystals. To note, the as-prepared RuNi1 catalyst exhibits excellent catalytic activity and stability for HOR in alkaline media, which is superior to those of Ru-Ni bimetallic nanocrystals, pristine Ru, and commercial Pt/C catalysts. Density functional theory (DFT) calculations suggest that isolation of Ni atoms on Ru nanocrystals not only optimizes the hydrogen-binding energy but also decreases the free energy of water formation, thus leading to excellent electrocatalytic activity of RuNi1 catalyst. The results show that engineering a catalyst at an atomic level is highly effective for rational design of electrocatalysts with high performance.