Surface Reconstruction in High‐Entropy OER Electrocatalysts: Mechanisms, Energy Consumption, and Design Principles

ABSTRACT Hydrogen production via water electrolysis is hindered by the sluggish kinetics of the oxygen evolution reaction (OER). High‐entropy materials (HEMs) show great promise due to their unique compositional tunability, though their performance is closely linked to surface reconstruction processes. This review systematically analyzes the impact of various reconstruction features on the OER performance of HEMs, with particular emphasis on the associated energy consumption. Based on reconstruction behaviors under practical operating conditions, these features are categorized into four types: (i) surface reconstruction leading to the formation of metal (oxy)hydroxide active layers; (ii) construction of crystalline/amorphous heterointerfaces; (iii) oxygen‐vacancy formation coupled with lattice oxygen participation; and (iv) synergistic reconstruction mechanisms. By evaluating the effects of these strategies on catalytic activity and durability, this review elucidates the intrinsic correlations between reconstruction pathways and catalyst performance. Furthermore, through systematic compilation and comparative analysis of reported data, optimal reconstruction strategies are identified from the perspectives of both overpotential and long‐term stability. Finally, design principles informed by reconstruction mechanisms are proposed to guide the development of high‐performance HEM‐based OER catalysts for diverse application scenarios, along with a discussion of current challenges and future opportunities for practical implementation.