Research progress and application of non-noble transition metal-based electrocatalysts in the hydrogen evolution reaction by water splitting

Abstract

As environmental pressures arising from continued fossil fuel consumption intensify, hydrogen has emerged as a clean, sustainable, and high-energy-density carrier for future energy systems. Among the available hydrogen production technologies, room-temperature water electrolysis is regarded as one of the most promising pathways. The electrocatalytic hydrogen evolution reaction (HER) constitutes the central half-reaction in water electrolysis; however, the reliance on scarce and expensive noble-metal catalysts severely limits large-scale deployment. Consequently, the development of highly active, durable, and cost-effective non-precious metal electrocatalysts has become a critical research focus. This review systematically summarises recent advances in non-precious-metal-based HER catalysts, encompassing transition-metal sulphides, phosphides, oxides, selenides, nitrides, carbides, and borides. Emphasis is placed on performance-enhancement strategies, including chemical doping, morphology engineering, heterostructure construction, and defect modulation, and their underlying mechanistic roles. By precisely tailoring electronic structures, active-site densities, and adsorption energetics of reaction intermediates, a wide range of non-precious metal catalysts have demonstrated outstanding HER activity in acidic, alkaline, and neutral electrolytes. Notably, under optimised conditions, some catalysts exhibit overpotentials, Tafel slopes, and long-term stability comparable to or even surpassing those of noble-metal benchmarks. Finally, this review summarises key performance evaluation metrics for HER electrocatalysts and discusses future research directions and industrial application prospects for non-precious transition-metal-based systems, providing valuable guidance for the development of efficient and economically viable hydrogen production technologies.