High‐Entropy Metal–Organic Framework‐Based Armor Catalysts for Electrocatalytic Water Splitting: A Comprehensive Review

ABSTRACT Electrocatalytic water splitting is pivotal for sustainable hydrogen production but is constrained by the sluggish kinetics of the oxygen evolution reaction (OER) and the inherent activity‐stability trade‐off. To address these limitations, high‐entropy metal–organic framework (HE‐MOF) based armor catalysts have emerged as a promising platform. This innovative design ingeniously combines the thermodynamic stabilization and synergistic effects of high‐entropy alloys with the structural tunability of MOFs. By constructing a robust protective “armor” around the active high‐entropy core, these catalysts successfully decouple intrinsic catalytic activity from long‐term durability, effectively mitigating key degradation pathways such as active‐site leaching and agglomeration. This comprehensive review systematically elucidates the fundamental principles of high‐entropy and core–shell armor architectures. We critically analyze advanced synthesis strategies and detail how electronic modulation and strain engineering optimize reaction intermediate adsorption. Their superior performance in pH‐universal hydrogen evolution, oxygen evolution, and overall water splitting is thoroughly discussed. Finally, current challenges and future perspectives toward AI‐guided design and scalable integration are outlined, providing a roadmap for next‐generation electrocatalyst development.