Self‐Adaptive Fe‐(O,N)‐C Interface Engineered on Spinel Iron Oxide for Enhanced Oxygen Evolution

ABSTRACT

Constructing stable, molecularly defined active interfaces on cost‐effective oxide supports is a pivotal yet unmet challenge in oxygen evolution reaction (OER) electrocatalysis, as conventional sacrificial or indirect strategies preclude direct control over the functional interface where catalysis unfolds. Herein, we demonstrate this concept on spinel iron oxide, achieving a robust Fe‐(O,N)‐C coordination shell on Fe ₃ O ₄ via dual‐ligand capture‐reorganization. Density functional theory predictions of favorable electronic modulation from this dual‐coordination are validated by operando spectroscopic and kinetic analyses. These reveal that the interface maintains dynamic stability under OER conditions, stabilizes high‐valent iron‐oxo species, and markedly enhances lattice oxygen participation, which provides fundamentally new insights into the self‐adaptive reconstruction and operational stability of molecularly tailored interfaces. Remarkably, this purely molecular engineering enables Fe ₃ O ₄ to overcome its sluggish reaction kinetics and inherent degradation tendency, achieving activity ( η ₁₀ = 252 mV, 49 mV lower than pristine Fe ₃ O ₄ ) and durability (only 0.17 mV h ⁻¹ decay over 300 h at 500 mA cm ⁻² , one‐fifteenth that of pristine Fe ₃ O ₄ over 120 h) that also rival those of complex heterostructured systems reported. This work establishes a conceptual paradigm of direct molecular interfacial control for oxide electrocatalysts, offering a design rationale for developing high‐performance materials for sustainable energy conversion.