Strongly Correlated Electron Systems in Triple Metal Atoms Trigger Atomic‐Level Structure Resonance for Durable and Efficient Ammonia Electrosynthesis

ABSTRACT Electrocatalytic nitrate reduction reaction (NO 3 RR) is an important route for achieving both sustainable ammonia synthesis and wastewater treatment. However, the weak electron correlation characteristics between the active sites in traditional catalysts leads to their limited dynamic adaptability, which highly restricts the construction of ammonia synthesis systems that simultaneously possess high selectivity, high yield rate, and high stability. Here, we synthesize a NiCoFeOOH multi‐metallic catalyst with strong electron coupling characteristics by inducing the electron‐spin‐geometric structure transformation via an in situ reconstruction strategy. NiCoFeOOH sustains high Faradaic efficiencies (FEs, 95%–99%) across a broad potential range together with a remarkable yield rate of 52 mg h −1 cm −2 . The catalyst remains stable for up to 324 h at the industrial current density of 1 A cm −2 (FEs ∼ 90%, a record‐breaking yield rate of ∼72 mg h −1 cm −2 ) in a membrane electrode assembly electrolyzer (MEA), ranking it among the most efficient and stable electrocatalysts reported hitherto. Operando/in situ characterizations combined with theoretical calculations show that atomic resonance between triple octahedral structural unit and key intermediate highly mediates the hydrogenation pathway. Based on the quantum spin exchange interaction, the adaptive charge transport channel among multiple atoms accelerates the proton‐coupled electron transfer kinetics and suppress atomic dissolution at ampere‐level current densities.