Fe‐Ni Synergy Reinforced by Zn Leaching: A Hydroxyl Spillover Pathway to Bridge the Gap Between Lattice Oxygen Activity and Robust Water Oxidation
Zhao‐Hua Yin, Yun‐Miao Fan, Kepeng Song, Long Chen, Hao Tan, Chaoqun Li, Yuping Zhang, Huigang Zhang, Jianjun Wang
Abstract
Abstract The sluggish lattice oxygen turnover kinetics and structural instability of catalysts under the lattice oxygen mechanism (LOM) severely hinder their practical application in the oxygen evolution reaction (OER). Herein, these challenges are addressed by strategically introducing Zn vacancies (Zn v ) through selective Zn leaching during electrochemical reconstruction. The Zn v ‐modified FeNiOOH framework stabilizes Fe sites, elevates their oxidation state, and enhances Lewis acidity, enabling Fe to act as a robust hydroxyl pump. This facilitates hydroxyl spillover, which expedites oxygen vacancy replenishment and lattice oxygen regeneration via an unconventional pathway. Density functional theory (DFT) reveals that Zn v optimizes the O 2p band center, strengthens metal‐oxygen covalency, and reduces hydroxyl migration barriers, collectively activating lattice oxygen for OER. The optimized catalyst achieves a remarkably low overpotential of 156 mV at 10 mA cm −2 and sustains industrial‐grade current densities (≥200 mA cm −2 ) for over 500 h with a 70‐fold reduction in decay rate. In situ spectroscopic and isotopic labeling studies confirm the dominant LOM pathway and rapid oxygen vacancy healing. This work establishes a paradigm for designing durable LOM‐driven electrocatalysts through precise vacancy engineering, bridging the gap between high activity and industrial stability.