Ammonia synthesis by electrochemical nitrogen reduction reaction - A novel energy storage way

Ammonia is a zero‑carbon, and high-energy storage feedstock. The Haber-Bosch process of industrial ammonia synthesis is the predominant method of ammonia synthesis worldwide. However, the shortages of high energy consumption and high pollution of Haber-Bosch process affect the global environment. The electrochemical nitrogen reduction reaction (ENRR), which is environmentally friendly and can be carried out at room temperature and pressure, may be an alternative method. In recent years, researchers have used different materials such as noble metal, non-noble metal, single-atom, and defect materials to obtain higher NH3 yield rates and better Faradaic efficiency. With the continued efforts of the researchers, it is believed that the industrialization of ENRR will be achieved in the future. •A systematic review of ENRR from the viewpoint of the origins is presented.•The detail mechanism and theoretical calculations of ENRR were reviewed.•The mainstream engineering techniques for enhancing the ENRR properties of materials are reviewed.