Review on Electrochemical Reduction of Nitrogen by Graphdiyne-Based Catalysts: Recent Advances and Outlook

The present industrial ammonia synthesis is overdependent on the Haber–Bosch process operating under harsh conditions, which consumes enormous global energy together with gigatons of greenhouse gas emissions annually. The electrochemical nitrogen reduction reaction (NRR) offers a green and sustainable approach to ammonia synthesis under mild reaction conditions while its efficiency has been plagued by sluggish reactivity. Recently, novel engineering of catalysts and the development of electrolyzers have highlighted compelling opportunities to optimize the performance of the electrochemical NRR. In this review, emphasis was paid to summarizing a novel family of graphdiyne-based nitrogen reduction electrocatalysts together with a brief introduction to the fundamentals of the electrochemical NRR. In the beginning, mechanisms of the electrochemical NRR are discussed, followed by the elucidation of different types of electrolyzers together with experimental aspects of catalyst evaluation. Then, the advances in graphdiyne-based electrocatalysts are highlighted. Finally, the critical challenges and outlook for the emerging paradigms in the rational design of nitrogen reduction electrocatalysts are proposed.