A cyanate-intermediate pathway for efficient electrosynthesis of urea over CuFe heterointerfaces

Electrochemical co-reduction of carbon dioxide and nitrate represents a sustainable alternative to the harsh conventional urea manufacturing. However, the complicated multistep process leads to a lack of fundamental understanding regarding the reaction pathways and the precise design of efficient electrocatalysts. Herein, we report a straightforward strategy to regulate the adsorption strengths of CO2 and NO3 –feedstocks by introducing Fe as a secondary element for efficient electrocatalytic C–N coupling. Further optimization of the microenvironment demonstrates that the optimal bimetallic catalyst with abundant heterogeneous interfaces delivers a maximum urea yield rate of 57.8 mmol h-1 g-1 at -1.6 V versus reversible hydrogen electrode, alongside robust recycling stability. Moreover, in situ spectroscopic measurements coupled with chemical control trials unveil a surface cyanate intermediate (*OCN) during the electrocatalytic C–N coupling, followed by the Wöhler reaction to form urea. These results verify dual-site heterostructured engineering as a promising approach for catalyst design and provide fresh insights into the reaction pathway of urea synthesis.