Multiscale Catalyst Design to Enhance Interfacial Hydroxyl Anion Supply and Accelerate Water Dissociation for Neutral Oxygen Evolution

Abstract Neutral water electrolysis faces challenges due to insufficient OH ⁻ supply, which leads to inefficient oxygen evolution reaction (OER). Constructing a localized OH ⁻ ‐enriched reaction environment is crucial for enhancing the neutral OER activity. Here, an integrated catalyst design aimed at optimizing the local reaction environment is presented to improve catalytic activity. Specifically, a high‐curvature needle morphology is constructed to strengthen the local electric field, which induces localized OH ⁻ accumulation and mitigates OH ⁻ deficiency in the neutral electrolyte. Moreover, implanting Ag cores not only improves the conductivity and long‐term stability of the NiCo‐based catalytic shells but also enables Ag diffusion to dope the catalytic layer. At the atomic scale, Ag dopants modify the activity of oxygen ligands and the polarity of metal‐oxygen (M─O) bonds within the symmetric spinel structure. This modification facilitates surface reconstruction, resulting in the formation of a distorted Ag‐O‐Ni/Co‐OH network. The elongation of the Ni/Co−O bond generates an inhomogeneous charge distribution that optimizes water polarization and deprotonation, accelerating water dissociation and *OH formation. The multiscale catalyst design results in a unique interface featuring a high‐curvature surface and atomic‐scale polarized M─O networks, synergistically enhancing local *OH accumulation. Therefore, the optimal Ag@NiCo ₂ O ₄ catalyst delivers a η ₁₀ = 295 mV in an H‐cell electrolyzer and 2.1 V @1 A cm ⁻² in a membrane electrode assembly electrolyzer. This finding provides a practical design for OER electrocatalysts in neutral electrolytes and opens a new avenue for optimizing catalytic performance by integrating multiple strategies.