Ammonia ranks as the world's second-most-produced chemical, with an annual production of approximately 180 million metric tons. Nearly all ammonia is manufactured through the Haber–Bosch process, which involves the reaction of hydrogen and atmospheric nitrogen at high temperatures and pressures. Typically, the hydrogen used is derived from natural gas. This process emits around 2.4 metric tons of carbon dioxide per ton of ammonia, accounting for about 2% of global annual carbon dioxide emissions.
A novel approach for synthesizing ammonia onsite under ambient conditions has been developed, employing a catalyst mesh made of magnetite (Fe3O4) combined with Nafion polymer.

The researchers in this Science Advances publication utilized the catalyst to process air, capturing microdroplets formed from atmospheric water vapor while using nitrogen from the air. This approach resulted in ammonia concentrations between 25 and 120 μM within one hour, varying with local relative humidity. Operating at room temperature and atmospheric pressure, the method avoids the need for additional electricity or radiation, significantly lowering carbon dioxide emissions compared to the conventional Haber-Bosch process.
Laboratory tests allowed further optimization of reaction conditions and scaling up of the procedure. After two hours of spraying, the ammonia concentration rose to 270.2 ± 25.1 μM. Additionally, a portable device was developed for onsite ammonia production, capable of consistently achieving concentrations suitable for certain agricultural irrigation needs.

Scientists have been exploring alternative, low-energy methods to produce ammonia. Some approaches focus on using renewable energy to split water for hydrogen, while others experiment with innovative techniques, such as employing lasers, to weaken nitrogen's strong bonds, making it more reactive with hydrogen.
In a recent study, researchers from Stanford University and King Fahd University of Petroleum and Minerals in Saudi Arabia developed a specialized catalyst mesh by coating copper mesh with iron oxide and a polymer. Air passed through the mesh condenses atmospheric water vapor into microdroplets, which then react with nitrogen to produce ammonia.
The team optimized and scaled up this process in laboratory conditions. They examined the effects of environmental factors such as humidity, wind speed, salt concentration, and acidity on ammonia production. Additionally, they analyzed the influence of water droplet size and the interaction between water and the mesh on the reaction efficiency.
Using these findings, the researchers designed a prototype device capable of producing ammonia onsite in outdoor settings. The device utilizes a suction pump to draw air into a chamber, where the catalytic mesh facilitates the reaction of nitrogen and water vapor. A condenser plate collects the ammonia-rich solution by separating it from air and water vapor.
The team envisions this portable device enabling sustainable, localized production of green ammonia. Once further developed, it could reduce dependency on large-scale industrial facilities and the associated transportation costs and emissions, contributing to a more sustainable agricultural ecosystem.