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.