(Invited) Catalyst-Free, Plasma-Driven Electrolytic Synthesis of Ammonia from Nitrogen and Water at Ambient Conditions

A plasma-driven electrolytic process has been developed to produce ammonia from nitrogen and water at ambient conditions. The system features a direct-current, atmospheric-pressure microplasma formed in a flow of nitrogen at the surface of an aqueous, acidic solution. By comparing ammonia yield against experimental controls, including argon gas, and measuring ammonia yield as a function of time, discharge current and solution pH, we show the faradaic efficiency reaches as high as 100%. We also uncover insights into the reaction mechanism by utilizing scavengers, which involves solvated electrons and hydrogen radicals preferentially reacting with nitrogenated species. We anticipate this technology will be promising for distributed ammonia production since it can operate at ambient conditions with only electricity, acidified water, and nitrogen gas as feedstocks.