Mimicking Enzymatic Proton Channeling Enables Near-Unity Selective Ammonia Electrosynthesis Beyond Neutral Limits

Fragmented hydrogen-bond networks relegate proton transport to sluggish diffusion, leading to mismatched proton supply that compromises catalytic efficiency and selectivity, thereby necessitating strategies to enhance water-network ordering. Inspired by the proton channel mechanism in enzymatic catalysis, this work anchors silicotungstate (SiW₁₂) onto Co₃O₄ to construct a SiW₁₂/Co₃O₄ catalyst. The domain electrostatic field of SiW₁₂ induces the ordered arrangement of interfacial water molecules, establishing an ordered water channel for proton migration. The results demonstrate that SiW₁₂ promotes interfacial water activation and alleviates proton-transfer limitations, enabling rapid and directional proton delivery to nitrogen-containing intermediates. Leveraging this unique proton channel, SiW₁₂/Co₃O₄ achieves near 100% selectivity over a wide potential window (-0.3 to -0.9 V vs. RHE) and a broad nitrate concentration range (0.01-1 M), achieving 99.3% NH₃ FE and 15.1 mg h^-1 cm^-2 yield at -0.8 V versus RHE. Furthermore, the assembled Zn-NO₃ ^- battery delivers the highest reported power density (26.1 mW cm^-2) under neutral conditions. This work establishes interfacial solvation-structure engineering as a general strategy for regulating proton delivery and developing highly selective electrocatalysts for sustainable ammonia electrosynthesis.