Review of High Entropy Alloys Electrocatalysts for Hydrogen Evolution, Oxygen Evolution, and Oxygen Reduction Reaction

Recently, high-entropy alloys (HEAs) have been extensively investigated due to their unique structural design, superior stability, excellent functional feature and superior mechanical performance. However, most of the reported HEAs focus on studying the compositional design and microstructure and mechanical properties of materials. There are relatively few studies on electrochemical performance and theoretical studies of HEAs. In addition, the potential applications of HEAs as energy storage materials for electrocatalysts have attracted widely attention in the development and application aspects of electrocatalysis. It can be attributed to their high conductivity, excellent structural stability and superior electrocatalytic activities with small overpotential and abundant active sites, which is comparable to the commercial noble metal catalysts. In this review, firstly, we briefly discuss the concept and structure characteristics of high entropy alloys. Then, the research progress of high-entropy alloys as electrocatalysis are also summarized, including hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), respectively. Finally, the future development trend of HEAs is also prospected for energy conversion fields.