Electrochemical strategies for urea synthesis via C–N coupling of integrated carbon oxide–nitrogenous molecule reduction

Abstract

The electrochemical coupling of C and N has sparked considerable research attention, heralded as a capable method to curb carbon and nitrogen emissions while concurrently storing surplus renewable electricity in valuable chemical compounds such as urea, amides, and amines. Electrocatalytic urea synthesis via a C–N coupling reaction (CNCR) comprises the electroreduction of CO₂ alongside the coreduction of various inorganic nitrogen sources (NO₃⁻, NO₂⁻, N₂, and NO). However, the main hurdles for this electrochemical C–N coupling are the inert nature of the involved molecules and the prevalence of competing side reactions. This review comprehensively examines recent advancements in electrocatalytic C–N coupling, emphasizing the various mechanistic pathways involved in urea production, including the CO₂ reduction and NO₃ reduction reaction. Additionally, electrochemical key performance parameters and future advancement directions for electrocatalytic urea production are discussed. The electrochemical CNCR accomplishes effective resource use and delivers direction and reference for molecular coupling reactions. The insights gleaned from these observations may illuminate the development of effective catalysts in forthcoming research and expand the potential applications in green urea production.