Continuous ammonia synthesis via cascaded gliding arc discharge and Co/Cu bimetallic oxide electrocatalysis in an...

Green ammonia synthesis driven by renewable energy is a promising low-carbon alternative to the conventional Haber-Bosch process. Recent studies have highlighted the great potential of plasma-electrocatalysis cascade strategies for this purpose. To advance such systems toward practical implementation, we developed an integrated reactor that enables simultaneous plasma oxidation and electrocatalytic NO_x^- reduction, achieving continuous ammonia synthesis directly from air and water. In this system, a gliding arc discharge employed to oxidize N₂ was optimized and diagnosed, delivering a low specific energy consumption (SEC) of 3.05 kW h mol^-1. Meanwhile, a Co₃O₄/CuO electrocatalyst was prepared, achieving an NH₃ yield rate of 0.84 mmol h^-1 cm^-2 with a Faradaic efficiency of 92.1%. More importantly, the integrated reactor demonstrates a pronounced synergistic effect: the plasma not only continuously supplies NO_x^- but also generates short-lived reactive species that promote the subsequent electrocatalytic reduction. Consequently, the cascade system achieves an NH₃ yield rate of 8.93 mmol h^-1 with an overall SEC of 4.06 kW h mol^-1 from N₂ to NH₃. This work demonstrates the unique advantages of integrated reactor coupling plasma and electrocatalysis, offering a promising pathway toward sustainable ammonia production.