Tailored high-entropy alloy nanomaterials for electrocatalytic applications

High-entropy alloy (HEA) nanomaterials have garnered extensive attention over the past few years for their intriguing properties over conventional simple alloys. The applications of HEA nanomaterials in electrocatalysis open prospective new avenues for catalyst discovery and performance optimization. The expansive compositional space, random atomic arrangement, and complex coordination environment endow HEA catalysts with tremendous tunability, which in turn calls for more effective and general design strategies in the catalysis community. An in-depth comprehension of the structure-performance relationship of HEA electrocatalysts is urgently needed to advance their reasonable development further. In this review, design methodologies of HEA nanomaterials are first discussed from four aspects, i.e., the composition, size, shape, and crystal structure, with the ultimate goal of achieving optimal catalytic activity, selectivity, and stability. Subsequently, recent progress in diverse electrochemical reactions, including hydrogen evolution, hydrogen oxidation, oxygen evolution, oxygen reduction, carbon dioxide reduction, alcohol oxidation and nitrate reduction, is summarized with a focus on the design principles of HEA catalysts toward specific reactions. Last, current tasks and future outlooks in this burgeoning field are proposed. Overall, this review is dedicated to leveraging the potential of HEA nanomaterials for efficient and sustainable energy storage and conversion. © 2025 Elsevier Ltd.