Design principles and emerging advances of high-entropy alloy electrocatalysts for hydrogen evolution

To advance the large-scale application of water electrolysis for hydrogen production, developing efficient, stable, and low-cost electrocatalysts is crucial for the continued advancement of this technology. High-entropy alloys (HEAs), leveraging unique effects such as configurational entropy and lattice distortion, offer a promising alternative to conventional catalysts. However, their vast compositional space and complex structure-property relationships present significant challenges for efficient screening and rational design. This review systematically summarizes recent advances in HEA electrocatalysts for the hydrogen evolution reaction (HER), focusing on their multidimensional rational design strategies. On the compositional−design front, we delve into functional-element screening, stoichiometric optimization, and non-metal doping, while advocating for a fundamental paradigm shift from“noble-metal dilution”to“noble-metal substitution.” We then categorize structural regulation strategies, covering diverse synthesis routes and the performance enhancements enabled by engineering materials across different dimensions (0D−3D). Notably, a critical examination is provided on the role of machine learning and high-throughput computation in accelerating catalyst discovery, highlighting not only successes but also inherent bottlenecks such as data bias and descriptor limitations. Finally, this review identifies three core barriers impeding the translation of HEA catalysts from laboratory to industry: persistent reliance on noble metals, poor batch reproducibility in synthesis, and the gap between idealized testing and industrial operating conditions. Corresponding future research priorities are proposed, including the development of more accessible, non-PGM-rich compositions, scalable and precise synthesis routes, and stability validation under industrial-current-density regimes. This work aims to establish a comprehensive “mechanism-design-application” framework to guide the development of next-generation, industrially viable HER electrocatalysts.