Driven by the escalating global demand for ammonia, developing efficient and environmentally benign synthesis methods has emerged as a critical research frontier. Traditional Haber-Bosch processes require harsh high-temperature and high-pressure conditions, which are highly energy-intensive and ill-suited for decentralized, small-scale applications. To address these sustainability challenges, this study investigates a green ammonia synthesis strategy utilizing an in-liquid discharge plasma electrochemical process, where water and nitrogen gas (N₂) serve as the hydrogen and nitrogen sources, respectively. The experimental setup features a customizable H-type interchangeable membrane plasma electrolytic cell. The plasma electrode consists of a stainless steel capillary recessed within a quartz tube, while an exposed tungsten wire serves as the counter electrode. Powered by a peristaltic pump, N₂ gas is introduced through the capillary into a sodium sulfate Na₂SO₄ aqueous electrolyte. Applying a direct current (DC) voltage beyond a specific threshold initiates localized plasma at the capillary tip to activate the inert N₂ molecules. An ion-exchange membrane is integrated into the cell to prevent the cross-mixing of anodic and cathodic gases, and the entire system is operated within a temperature-controlled water bath. We systematically evaluate the effects of key operational parameters, including gas flow rate, discharge current, discharge polarity, water bath temperature, and electrolyte circulation rate, on the faradaic efficiency and yield of ammonia formation. Furthermore, the underlying chemical mechanisms and reaction pathways of plasma-induced N₂ activation and reduction are discussed, providing insights for optimizing green ammonia production.
 

ammonia; plasma electrochemical process; H-type cell