Constructing Novel High‐Entropy Alloy Aerogels Platform for pH‐Universal Hydrogen Evolution Reaction with High Electrocatalytic Activity and Stability

Abstract Development of high‐performance hydrogen evolution reaction (HER) electrocatalysts that are both efficient and stable across a wide pH range is significant but remains challenging. In this study, an innovative methodology utilizing an ultrasonic‐assisted strategy is proposed for efficiently synthesizing diversiform high‐entropy alloy aerogels (HEAAs). It is substantiated that the prepared HEAAs represented by quinary PdPtRhRuAu show outstanding electrocatalytic activity and stability for pH‐universal HER, which comparable or superior the commercial Pt/C, as well as the majority of currently reported HER electrocatalysts. Theoretical calculations reveal that the enhanced electrochemical activity of HEAAs within universal pH originated from the multiple catalytic active sites due to the synergetic effects of different elements and the unsaturated coordination state, which optimizes the adsorption behavior of intermediates in elementary reactions. This work not only provides a versatile synthetic method for multi‐element constituted HEAAs, but also discovers the intrinsic reason of high catalytic performance for synthesized HEAAs thus benefitting the development of multifunction catalysts.