Electrocatalytic Reduction of Nitrogen to Ammonia in Ionic Liquids

Ammonia (NH3) is an important raw material for nitrogen fertilizer production and is widely used in industry. It is also a carbon-free renewable fuel and an excellent hydrogen storage material. Reaction conditions of the traditional Haber–Bosch process are very harsh even though it supports most of today’s NH3 production. Recently, the electrocatalytic nitrogen reduction reaction (NRR) has become one of the effective alternative methods to the traditional Haber–Bosch process due to the advantages of mild operation conditions and almost no environmental pollution. Ionic liquids (ILs) act as one of the green solvents that possess a lot of unique features and have shown excellent performance in the electrocatalytic NRR process. In this perspective, we summarize the fundamentals of the electrocatalytic NRR, the role of ILs in several typical electrocatalytic processes, and the possible role of ILs in the electrocatalytic NRR process. Moreover, the selection principles and issues of the application of ILs as well as the future development directions for the electrocatalytic NRR process are presented.