Self‐Activating Electrocatalysts for Water Splitting: Advancing Structure–Performance Understanding and Beyond

ABSTRACT Self‐activating electrocatalysts represent an emerging paradigm in water‐splitting catalysis, shifting the focus from static materials toward adaptive, dynamically evolving interfaces under electrochemical bias. Yet, a unified understanding of the mechanisms that govern their structure–performance relationships remains limited. This review provides critical mechanistic insights and highlights cutting‐edge developments that illuminate catalyst evolution under operating conditions. We summarize recent advances in self‐activating catalysts for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), emphasizing the key driving forces behind enhanced activity and stability, including catalyst–electrolyte interfacial evolution, catalyst–support interaction, morphology, and crystallinity adaptation. By integrating and comparing frequently used mechanistic descriptors, we establish a conceptual framework that captures the core features of self‐activation across both OER and HER. Finally, we identify current knowledge gaps and outline future research directions that may accelerate the translation of self‐activating electrocatalysts toward scalable, cost‐effective, and sustainable hydrogen production.