Progresses on high-entropy nano-catalysts for electrochemical energy conversion reactions

Nanostructured high-entropy materials (HEMs) have garnered significant attention as a burgeoning class of materials in electrocatalysis due to their exceptional structural and functional properties. Many milestones have been achieved in the last few years, making a timely review of these progresses critically important for the further development of this promising research area. Herein, we provide a comprehensive review of recent advances in nanosized HEMs, starting with the well-developed synthesis methods and characterization technologies. Then, the applications of HEM for energy conversion reactions such as hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, carbon dioxide reduction, and methanol oxidation reaction will be fully discussed in detail with typical examples reported recently. Further, the optimization strategies to improve the catalytic performance of HEMs are proposed. Finally, the challenges are outlined with the purpose of establishing future research opportunities for the rational design of HEM-based electrocatalysts towards efficient energy conversion reactions. This review provides a comprehensive discussion of the recent progresses of nanostructured HEMs as electrocatalysts for energy conversion reactions, with emphasis on the structure-composition-property-performance relationship of the HEMs.