Engineering NiRu Nanoalloys on N-Doped Carbon Nanocages for Efficient Electrocatalytic Hydrogen Oxidation Reaction

Abstract

Hydrogen, characterized by its high energy density, efficiency, and environmentally benign output, emerges as a promising alternative to fossil fuels. However, the development of robust hydrogen oxidation reaction (HOR) catalysts for efficient energy conversion remains a significant challenge. Herein, a NiRu nanoalloy catalyst supported on N-doped hollow carbon nanocages (NiRu/NC) is synthesized via a tandem pyrolysis method. The NiRu/NC catalyst exhibits superior alkaline HOR activity, achieving diffusion-limited current density of 2.56 mA cm^–2 and maintaining stability for 80,000 s with a decay rate of only 5.9%, compared to a 28.7% decay rate for benchmark Pt/C after 35,000 s. Additionally, it demonstrates remarkable resistance to CO poisoning, with the current density decreasing by only 50.7% after 1800 s, while the current density of Pt/C dropped to 0 after 800 s. Density functional theory calculations indicate that Ni in the NiRu nanoalloy effectively modulates the electron distribution, thereby ameliorating the electronic structure and enhancing the adsorption of reaction intermediates. These optimizations endow NiRu/NC with both favorable hydrogen-binding energy (HBE) and hydroxyl-binding energy (OHBE), leading to improved HOR efficiency. This work not only offers an innovative approach for synthesizing high-performance alloy-based HOR catalysts but also deepens the fundamental understanding of the bimetallic synergistic mechanisms in HOR catalysis.