Directional CO spillover promotes C–N coupling for highly selective electrocatalytic urea production
Abstract
Electrocatalytic co-reduction of nitrate (NO3−/NO2−) and CO2 to urea offers a sustainable pathway for simultaneous wastewater remediation and fertilizer synthesis, but its efficiency is plagued by sluggish C–N coupling kinetics and a mismatched reaction rate of CO2 and NO3− reduction. Herein, we design a tandem electrode composed of zinc nanoparticles on copper nanowires that spatially decouples NO3− activation and *CO generation, enabling directional intermediate spillover for enhanced C–N coupling. The minimized work function difference between Zn and Cu facilitates spontaneous *CO migration from Zn (CO2 → *CO) to Cu (NO3− → *NH2), achieving a faradaic efficiency of ∼99% and a urea production rate of 191.2 μg h−1 cm−2 at ultralow overpotential. In situ Raman and density functional theory calculations confirm that this architecture circumvents kinetic limitations of single-site catalysts by segregating and synchronizing key intermediates. Our work establishes a paradigm for precision control in multi-reactant electrocatalysis through spatially modulated tandem active sites.