Recent Advances and Perspective on Electrochemical Ammonia Synthesis under Ambient Conditions

Ammonia is an essential chemical for agriculture and industry. To date, NH3 is mainly supplied by the traditional Haber–Bosch process, which is operated under high-temperature and high-pressure in a centralized way. To achieve ammonia production in an environmentally benign way, electrochemical NH3 synthesis under ambient conditions has become the frontier of energy and chemical conversion schemes, as it can be powered by renewable energy and operates in a decentralized way. The recent progress on developing different strategies for NH3 production, including 1) classic NH3 synthesis pathways over nanomaterials; 2) the Mars-van Krevelen (MvK) mechanism over metal nitrides (MNx); 3) reducing the nitrate into NH3 over Cu-based nanomaterial; and 4) metal–N2 battery release of NH3 from LixM. Moreover, the most recent advances in engineering strategies for developing highly active materials and the design of the reaction systems for NH3 synthesis are covered.