https://phys.org/news/2018-10-milder-ammonia-synthesis-method-environment.html

Ammonia is important for producing nitrogen fertilizer. It also has the potential to store and transport renewable energy. However, current ammonia production is very energy intensive—consuming 1 to 2 percent of world energy output. In addition, about 1.9 metric tons of carbon dioxide is produced for every metric ton of ammonia.

"In order to address the challenges of the energy and environmental crisis, we developed an alternative process for ammonia synthesis from nitrogen gas, water and renewable energy," said Chen, the study's lead researcher.