New Plasma-Electrolysis Process Produces Ammonia from Air
Researchers at the University of Sydney have developed a new method for synthesizing ammonia gas directly from air using electricity, eliminating the need for hydrogen feedstocks and reducing reliance on the Haber-Bosch process. The approach could offer the chemical industry a decentralized, lower-emission pathway for ammonia production, with potential applications in green energy, shipping fuels and hydrogen transport.
The method uses a plasma system to energize nitrogen and oxygen molecules in ambient air. These excited molecules are then fed into a membrane-based electrolyzer, where they are converted into gaseous ammonia (NH₃). According to the research team, previous attempts at non-Haber-Bosch routes produced ammonium in solution (NH₄⁺), which required additional steps to obtain usable NH₃ gas.
This two-step plasma-electrolysis process, published in Angewandte Chemie International Edition, provides a more direct route to ammonia in its usable form. The researchers report that the plasma component is already energy-efficient and scalable. Current efforts focus on improving the energy efficiency of the electrolyzer to make the process competitive with traditional methods.
Ammonia’s role as a hydrogen carrier and carbon-free fuel has drawn growing interest from sectors such as maritime transport. The ability to generate NH₃ on-site and at smaller scales could reduce the need for centralized production and long-distance distribution.
The work was led by PJ Cullen from the University of Sydney’s School of Chemical and Biomolecular Engineering and the Net Zero Institute. His team has been pursuing green ammonia research for six years.
