Synergistic coupling of CO₂ and NO₃⁻ for efficient electrosynthesis of urea using oxygen vacancy-rich Ru-doped CeO₂ nanorods

The electrocatalytic C-N coupling process for urea synthesis, driven by renewable energy resources, can replace the energy-intensive and environmentally harmful industrial production of urea. However, achieving improvements in both urea yield and Faradaic efficiency for urea synthesis is currently challenging. Herein, advanced oxygen vacancy-rich Ru-doped CeO₂ catalysts were developed for urea synthesis. The optimized 5% Ru-CeO₂ exhibited a high urea yield of 20.2 mmol h⁻¹ g⁻¹ and an excellent Faradaic efficiency of 20.1% at −0.7 V vs. reversible hydrogen electrode, surpassing the performance of most reported catalysts. Experimental results reveal that the synergistic effect of Ru doping and oxygen vacancies optimize the adsorption and activation of reactants, which facilitates the kinetics of C-N coupling and significantly improves the efficiency of the electrochemical urea synthesis. This study provides a promising strategy for developing advanced C-N coupling catalysts to achieve efficient urea synthesis.