Three birds with one stone: Electrocatalytic C–N coupling for carbon neutrality, nitrogen resource utilization, and urea synthesis

The industrial production of urea is accompanied by high energy consumption and huge carbon emissions, which hinder green and sustainable development. The combination of carbon dioxide (CO2) with ubiquitous nitrogen sources (nitrate, nitrite, nitric oxide, and nitrogen) through electrocatalysis C–N coupling to produce urea is a promising strategy of three birds with one stone, which can simultaneously promote carbon neutrality, efficient utilization of nitrogen resources, and the production of high value-added urea. However, the low urea yield (μmol to mmol level) and faradaic efficiency (<50 %), suboptimal reaction current density (<100 mA cm−2) and ambiguous C–N coupling mechanism severely limit the further development of the electrocatalytic urea synthesis. In this review, we present the progress of electrocatalytic urea synthesis by combining CO2 and different nitrogenous species under ambient conditions. The mechanisms of C–N coupling are summarized and the urea detection methods are evaluated in detail. More importantly, the techno-commercial analyses of electrocatalytic urea synthesis are provided. Furthermore, the current challenges and future opportunities are presented to realize the large-scale application of electrocatalytic urea synthesis as soon as possible.