Electrochemistry of Urea Synthesis via Carbon Dioxide Reduction: Mechanisms and Material Insights

Abstract

Electrocatalytic urea synthesis offers a sustainable, carbon- and energy-efficient alternative to the Haber-Bosch process under ambient conditions. It is a sustainable strategy in which simultaneous reduction of carbon dioxide (CO₂) and nitrogen molecules (nitrogen, nitrate, nitrite, nitric oxide, etc.) lead to form urea. However, electrochemical urea synthesis faces multiple challenges including activation of CO₂ and nitrogen molecules (nitrogen, nitrate, nitrite, nitric oxide, etc.), low production and selectivity toward urea production. The C–N coupling reaction is considered the most challenging part for urea synthesis. With respect to all this, this review focuses on fundamental reaction mechanisms followed by recent progress for electrochemical urea production. Recent advances highlight the rational design of heterogeneous catalysts─ranging from transition-metal-based systems (Cu, Ni, Fe, Co) to single-atom catalysts─that enable simultaneous activation of CO₂ and nitrogen molecules. This review summarizes proposed reaction pathways by correlating catalyst active centers with mechanistic insights into CO₂/N-containing species activation and coupling. The critical challenges related to low yield and Faradaic efficiency are outlined, providing perspectives for translating laboratory breakthroughs into practical urea electrosynthesis technologies. Collectively, these advances establish electrocatalytic urea synthesis as a frontier in sustainable chemistry, bridging carbon capture with nitrogen cycle management, and paving the way toward scalable green urea production.