Constructing Cu/ <scp> Cu ₂ O </scp> Heterogeneous Interface for Efficient Urea Electrosynthesis

Electrocatalytic coupling of CO 2 and enables urea synthesis under mild conditions while simultaneously converting greenhouse gases/pollutants, yet suffers from sluggish C–N coupling kinetics and low efficiency. To address this, a novel Cu/Cu 2 O catalyst with a high‐density heterogeneous interface and 3D crosslinking network structure was constructed. The high‐angle annular dark‐field scanning transmission electron microscope reveals the Cu/Cu 2 O heterogeneous interface at the atomic scale, showing a distinct contrast discontinuity that defines the metal/metal oxides phase boundary. This unique structure exposes a large number of dual active sites. In‐situ attenuated total reflection‐surface enhanced infrared absorption spectroscopy and density functional theory calculations revealed a space‐separated activation mechanism induced by the dual active sites at the heterogeneous interfaces. The electron‐deficient Cu site preferentially activates CO 2 to produce *CO, while the electron‐rich Cu 2 O site dominates reduction to form *NOH intermediates. The built‐in electric field formed at the heterogeneous interface further promotes the efficient C–N coupling of *CO and *NOH, significantly reducing the reaction energy barrier. Electrochemical tests showed Cu/Cu 2 O outperformed Cu and Cu 2 O in electrocatalytic coupling of CO 2 and for urea synthesis, achieving a record urea yield rate of 1156.63 mmol g −1 h −1 with 29.67% Faradaic efficiency at −1.0 V (vs RHE).