Chem
ReviewElectrochemical ammonia synthesis: Mechanistic understanding and catalyst design
The bigger picture
Ammonia, the second largest synthetic chemical commercialized worldwide, is widely used as a fertilizer and is a key intermediate for production of all nitrogen-atom-containing chemicals. It could also be employed for fueling applications. Electrochemical N2 reduction reaction (NRR) offers a renewable and distributed route for NH3 production. Heightened research efforts have focused on the design and development of advanced electrocatalysts to enhance the efficiency of NRR to make it competitive against the Haber-Bosch process from the economic and ecological viewpoints. We describe the latest advances in the NRR from both theoretical and experimental aspects and provide a guide on how electrocatalysis of NRR could be improved. We discuss the roles of emerging in situ and operando methods in elucidating the dynamic catalyst structure and other reaction parameters. The possible reaction pathways and the major challenges in improving the NRR are also highlighted.