The electrochemical coreduction of carbon dioxide (CO2) and nitrogenous species (such as NO3-, NO2-, N2, and NO) for urea synthesis under ambient conditions provides a promising solution to realize carbon/nitrogen neutrality and mitigate environmental pollution. Although an increasing number of studies have made some breakthroughs in electrochemical urea synthesis, the unsatisfactory Faradaic efficiency, low urea yield rate, and ambiguous C-N coupling reaction mechanisms remain the major obstacles to its large-scale applications. In this review, we present the recent progress on electrochemical urea synthesis based on CO2 and nitrogenous species in aqueous solutions under ambient conditions, providing useful guidance and discussion on the rational design of metal nanocatalyst, the understanding of the C-N coupling reaction mechanism, and existing challenges and prospects for electrochemical urea synthesis. We hope that this review can stimulate more insights and inspiration toward the development of electrocatalytic urea synthesis technology.
Keywords: advanced in situ characterization techniques; catalyst design; electrocatalytic C−N coupling; electrochemical coreduction of CO2 and nitrogenous species; heterogeneous catalysis; high-value-added chemicals; reaction mechanisms; urea electrosynthesis.