Electrocatalytic nitrate reduction to ammonia: catalyst design, electrolyte engineering and application scenarios.

The nitrate accumulation in aquatic environments can be converted into ammonia (NH3) by electrochemical reduction, possessing a great potential to replace the Haber-Bosh (HB) process for green NH3 synthesis, which is of great significance in promoting modern agriculture and carbon-free energy systems. In recent years, significant advances in NH3 electrosynthesis via the nitrate reduction reaction (NO3RR) have been achieved. Previous reviews have provided valuable perspectives on catalyst development and mechanistic understanding of NO3RR. Here, we provide an integrated perspective centered on the catalyst design, electrolyte engineering, mechanism insight, and emerging application scenarios. Particular emphasis is focused on how these aspects collectively govern NO3RR performance and its progression toward practical NH3 production. Meanwhile, future perspectives are proposed to accelerate industrialized NH3 production, ultimately establishing a sustainable nitrogen cycle via a nitrogen-based electrochemical process.