Recent Advances in Electrochemical Synthesis of Ammonia through Nitrogen Reduction under Ambient Conditions

Ammonia is an important chemical raw material, widely used in industry and agriculture, as well as an important energy storage intermediate and carbon-free energy carrier. But, its production is limited to the traditional Haber-Bosch process. Recently, electrochemical reduction of N-2 has been attracting more and more attention, owing to the lower energy consumption and because it is environmentally friendly. However, there are a lot of problems that remain to be solved, and the main challenges are the low selectivity and catalytic activity when using this process. In this Review, we first summarize the recent development of electrocatalysts for electrochemical N-2 reduction and elaborate on the reaction mechanisms of the nitrogen reduction reaction (NRR). In addition, the effects of different types of electrolyte on the NRR activity and electrolyte choice are discussed. Finally, the perspectives of electrochemical nitrogen reduction for conversion to ammonia are discussed.