Lattice‐Engineered Dual‐Electron‐Drive Electrode for Selective Ammonia Production From Nitrate

Abstract

ABSTRACT Ammonia (NH 3 ) is indispensable in agriculture and emerging energy systems, yet its conventional production remains energy‐ and carbon‐intensive. Electrochemical nitrate reduction reaction (NO 3 − RR) represents a promising alternative for sustainable NH 3 synthesis but is hampered by slow kinetics and low selectivity under realistic, neutral conditions. Here, we employ the lattice engineering strategy to construct a cobalt‐doped nanoscale zerovalent iron (Co‐nFe 0 ) electrode that integrates a dual‐electron‐drive mechanism with a self‐triggered alkaline microenvironment to overcome these challenges. Cobalt doping modulated the surface Fe electronic structure to create electron‐deficient Fe sites, which enhanced charge transfer, promoted water dissociation into active hydrogen species, and facilitated the hydrogenation of reaction intermediates. This design enabled an NH 3 Faradaic efficiency of 96% and near‐quantitative selectivity across a wide nitrate concentration range (100–1000 mg L −1 NO 3 − ‐N), alongside sustained operational stability. An insitu NH 3 recovery system could provide stable operation over 360 h and deliver 13 g day −1 NH 3 production with 100% NH 3 recovery. Rice pot experiments demonstrated that the recovered ammonium sulfate (99% purity) performed comparably to commercial fertilizers. This work provides an efficient electrocatalyst that couples electronic structure modulation and interfacial microenvironment regulation, thereby offering a sustainable technological route for nitrogen upcycling and green fertilizer production.