The progresses in electrochemical reverse artificial nitrogen cycle

The conventional artificial nitrogen cycle is mainly based on heterogeneous catalysis, such as the Haber-Bosch process for ammonia synthesis and Ostwald process for nitric acid production. However, these chemical processes are not sustainable. Recently, an electrocatalysis-based reverse artificial nitrogen cycle (eRANC) has been proposed, which follows the order of N2 → NOx → NH3 → N2 and provides a new route for ammonia and nitric acid synthesis. Herein, we have reviewed the recent progresses in electrochemical nitrogen oxidation (eN2OR) and nitric oxides reduction reactions (eNOxRR) from the aspects of activity, selectivity, and reaction mechanisms. We also summarized the challenges and provided advices for the future studies.