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Electrocatalytic nitrogen reduction (eNRR) offers a green pathway for NH3 production from N2 and H2O under ambient conditions. Transition metal oxynitrides (TMOxNy) are among the most promising catalysts but face challenges in achieving high yield and faradaic efficiency (FE). This work develops a hybrid WOxNy/WO3 catalyst with a unique heterogeneous interfacial complexion (HIC) structure. This design enables in situ generation and delivery of highly active hydrogen atoms (H*) in acidic electrolytes, promoting nitrogen hydrogenation and formation of nitrogen vacancies (Nv) on the WOxNy surface. This significantly enhances the selectivity of eNRR for NH3 synthesis while suppressing hydrogen evolution reaction (HER). A simple two-step fabrication process—microwave hydrothermal growth followed by plasma-assisted surface nitridation—was developed to fabricate the designed catalyst electrode, achieving an NH3 yield of 3.2 × 10-10 mol·cm-2·s-1 with 40.1% FE, outperforming most TMN/TMOxNy electrocatalysts. Multiple control experiments confirm that the eNRR follows a HIC-enhanced Mars-van Krevelen (MvK) mechanism. 

Non-equilibrium plasma has been found to have a synergistic effect on catalytic synthesis of NH₃. 

Abstract Manipulating surface charge, electric field, and plasma afterglow in a non-equilibrium plasma is critical to control plasma-surface interaction for plasma catalysis and manufacturing. Here, we show enhancements of surface charge, electric field during breakdown, and afterglow by ferroelectric barrier discharge. The results show that the ferroelectrics manifest spontaneous electric polarization to increase the surface charge by two orders of magnitude compared to discharge with an alumina barrier. Time-resolved in-situ electric field measurements reveal that the fast polarization of ferroelectrics enhances the electric field during the breakdown in streamer discharge and doubles the electric field compared to the dielectric barrier discharge. Moreover, due to the existence of surface charge, the ferroelectric electrode extends the afterglow time and makes discharge sustained longer when alternating the external electric field polarity. The present results show that ferroelectric barrier discharge offers a promising technique to tune plasma properties for efficient plasma catalysis and electrified manufacturing.