Recent advances in high-entropy alloys for electrochemical hydrogen evolution, oxygen reduction, and CO2 reduction reactions

High entropy alloys (HEAs) have gained significant attention in electrocatalysis research due to their distinctive multi-element composition, intricate electronic structure, and superior properties. By harnessing multi-component synergy, precise electron regulation, and the high-entropy effect, HEA electrocatalysts exhibit remarkable catalytic activity, selectivity, and stability. These materials demonstrate outstanding catalytic performance in a variety of electrocatalytic small molecule reduction reactions, including oxygen reduction (ORR), hydrogen evolution (HER), and CO₂ reduction (CO₂RR), making them promising candidates for clean energy conversion and storage applications, including fuel cells, metal-air batteries, water electrolysis, and CO₂ conversion technologies. This review highlights recent advancements in HEA electrocatalyst research, focusing on their synthesis, characterization, and applications in electrocatalytic small molecule reduction reactions. It also explores the underlying mechanisms of the high-entropy effect, multi-component synergy, and structural design. Finally, it discusses key challenges that remain in the application of HEAs for electrocatalytic small molecule reduction and outlines potential directions for future development in this field.