A Universal Approach for Sustainable Urea Synthesis via Intermediate Assembly at the Electrode/Electrolyte Interface

Electrocatalytic C-N coupling process is indeed a sustainable alternative for direct urea synthesis and co-upgrading of carbon dioxide and nitrate wastes. However, the main challenge lies in the unactivated C-N coupling process. Here, we proposed a strategy of intermediate assembly with alkali metal cations to activate C-N coupling at the electrode/electrolyte interface. Urea synthesis activity follows the trend of Li+<Na+<Cs+<K+. In the presence of K+, a world-record performance was achieved with a urea yield rate of 212.8 +/- 10.6 mmol h-1 g-1 on a single-atom Co supported TiO2 catalyst at -0.80 V versus reversible hydrogen electrode. Theoretical calculations and operando synchrotron-radiation Fourier transform infrared measurements revealed that the energy barriers of C-N coupling were significantly decreased via K+ mediated intermediate assembly. By applying this strategy to various catalysts, we demonstrate that intermediate assembly at the electrode/electrolyte interface is a universal approach to boost sustainable urea synthesis. The electrocatalytic C-N coupling shows great potential in sustainable urea synthesis. We proposed a universal strategy of intermediate assembly with alkali metal cations to activate C-N coupling at the electrode/electrolyte interface. Urea synthesis activity follows the trend of Li+<Na+<Cs+<K+. With 1.0 M of K+, a world-record urea yield rate of 212.8 +/- 10.6 mmol h-1 g-1 has been achieved on a single-atom Co decorated TiO2 catalyst.+image