Single Ga‐Atom Stabilized Cu ⁺ –Cu ⁰ Interfacial Sites for Efficient Air Plasma‐Derived Ammonia Electrosynthesis

ABSTRACT Electrocatalytic NO x reduction to ammonia (NO x RR) offers a sustainable route for decentralized NH 3 synthesis, however, its practical implementation is impeded by sluggish hydrogenation kinetics and the instability of active species. Herein, we develop a Ga single‐atom decorated CuO x /Cu (Ga SA ‐CuO x /Cu) catalyst featuring a strongly coupled Ga–O–Cu coordination structure. The introduction of highly electrophilic Ga 3+ modulates the electronic structure of Cu via p–d interactions, downshifting the Cu d ‐band center to weaken excessive intermediate binding, while stabilizing Cu + species to form highly active Cu + –Cu 0 interfacial sites. Meanwhile, Ga sites promote active hydrogen supply and accelerate hydrogenation kinetics on adjacent Cu centers. Benefiting from these synergistic effects, the optimized Ga SA ‐CuO x /Cu achieves a remarkable NH 3 Faradaic efficiency (FE) of 96.21% at −0.4 V versus RHE and high durability at −0.5 A cm −2 . Moreover, a Zn‐NO 2 − /ethanol battery delivers a peak power density of 17.47 mW cm −2 with improved charging efficiency, while a plasma‐assisted hybrid electrolyzer achieves >95% FEs for both NH 3 and formate at −400 mA cm −2 and operates stably for 200 h at 0.5 A cm −2 , demonstrating its strong applicability in integrated energy‐chemical conversion systems.