Stretching Metal─Oxygen Bonds to Decouple Activity and Stability of Water Electrolysis

Abstract The lattice oxygen‐mediated (LOM) mechanism offers a promising pathway to improve oxygen evolution reaction (OER) kinetics in alkaline water electrolysis by facilitating direct O─O bond formation. However, its practical utility in nickel‐iron layered double hydroxides (NiFe‐LDHs) is significantly restricted by the formation of high‐valent metal species (e.g., Ni 3 ⁺/Ni⁴⁺, Fe⁴⁺) during oxygen evolution. These species induce structural instability caused by metal overoxidation, leading to accelerated catalyst degradation under industrial current densities (>500 mA cm −2 ). Herein, this study challenges the conventional wisdom of pursuing unstable high‐valent metal species by a novel strategy that employs stabilized low‐valent Ni and Fe. Such an approach fundamentally circumvents the degradation pathway associated with over‐oxidation. Combined with strategic M─O bond elongation, the proposed method enhances LOM activity while preserving the structural integrity, thereby decoupling the traditional trade‐off between catalytic activity and stability. The resulting NiFe‐LP catalyst exhibits an ultralow overpotential of 219 mV and demonstrates remarkable operational stability, sustaining performance for over 1000 h at 5 A cm −2 in anion exchange membrane water electrolyzers (AEMWEs). This work redefines LOM as a feasible route for industrial‐scale water electrolysis by addressing its inherent instability through strategic metal─oxygen bond engineering.