Research advances in high-entropy alloy catalysts for water electrolysis under acidic conditions.

[Display omitted] • HEA catalysts for electrolysis under acidic conditions summarized. • Differences between PEMWE and alkaline water electrolysis discussed. • HEA catalysts categorized based on presence of precious metals. • The future of HEA catalysts for water electrolysis is envisioned in the manuscript. The gradual deterioration of the energy environment has led to excessive carbon dioxide emissions, making it urgent to seek more environmentally friendly alternative energy sources. In this context, hydrogen as a green energy source has become increasingly important. Currently, water electrolysis is one of the main methods for hydrogen production. The ultimate goal of hydrogen production industry is to produce green hydrogen using renewable energy sources. Compared to the currently widely commercialized alkaline electrolysis (ALK), the initial commercialization of proton exchange membrane (PEM) electrolysis has many advantages, including short start-up time, high current density, high load elasticity, and high operating pressure. Commercial acidic water electrolysis usually relies on precious metal-based catalysts such as Ir/Pt, but high-entropy alloys are expected to reduce the use of precious metals, thereby saving costs, and high-entropy alloys have the characteristic of corrosion resistance. This paper introduces the latest research progress in the field of high-entropy alloy acidic water electrolysis catalysts, briefly outlining the advantages of acidic water electrolysis, and summarizing the progress of high-entropy alloy catalysts in HER and OER, as well as classifying based on the presence of precious metals. Finally, the challenges and opportunities faced by high-entropy alloy catalysts for acidic water electrolysis are discussed. [ABSTRACT FROM AUTHOR]