Electrocatalytic C–N coupling for urea synthesis: a critical review

Urea is one of the most important artificial nitrogen fertilizers in the agricultural economy and can provide essential nitrogen for plant growth. However, the industrial production of urea is very energy consumptive. In the past few years, the electrocatalytic approach has been regarded as a promising green approach for urea synthesis under mild conditions. Therefore, using carbon dioxide (CO₂) and nitrogenous molecules as feedstocks, electrocatalytic urea synthesis has received extensive interest and investigation. Despite the tremendous efforts that have been made, it is still very hard to significantly increase urea synthetic efficiency due to complex mechanisms. Focusing on catalyst design, characterization, electrolytic cells chosen, urea identification/quantification, determination of intermediates, and in-depth mechanisms, the recent advances in urea electrocatalytic production are summarized and discussed. Furthermore, we analyze the current challenges and prospects for the development path of electrocatalytic urea synthesis. From an application viewpoint, we hope these insights shed light on designing efficient catalysts in future studies and bring broader application prospects for green urea synthesis.