Reconstructed Cu ₂ O@CuCo Heterostructure with Accelerated Hydrogenation Kinetics for Air Plasma-Derived Ammonia Synthesis

Ammonia (NH3) is a key chemical for sustainable energy and nitrogen utilization, and air plasma-derived electrochemical NH3 synthesis offers a promising alternative to traditional methods, yet significant challenges remain. Here, we develop an R-Cu2O@CuCo catalyst with abundant heterogeneous interfaces and strong electronic interactions via a facile chemical synthesis and electroreduction reconstruction strategy, exhibiting excellent NO2–-to-NH3 performance. Benefiting from the efficient activation of active hydrogen intermediates by R-Cu2O@CuCo, NH3 Faradaic efficiencies (FE) exceeding 90% are achieved over a wide voltage range (0 V vs RHE to −0.5 V vs RHE), with maximum FE and NH3 yield reaching 95.4% at −0.1 V vs RHE and 1.22 mmol h–1 cm–2 at −0.6 V vs RHE, outperforming most reported catalysts. More importantly, a complete NH3 synthesis system is realized by integrating spark discharge plasma for air-to-NOx– conversion and electrocatalytic reduction of NOx–-to-NH3 using R-Cu2O@CuCo in a membrane electrode assembly (MEA) electrolyzer, enabling real-time NH4Cl product separation. Furthermore, demonstrating practical applicability, a Zn-NO2– battery achieves a high NH3 production rate, maximum power density of 6.35 mW cm–2 and outstanding stability. This work paves the way for the development of advanced catalysts for continuous and efficient energy conversion systems.