Rectifying Heterointerface Facilitated C−N Coupling Dynamics Enables Efficient Urea Electrosynthesis Under Ultralow Potentials

Abstract

Electrocatalytic C−N coupling for urea synthesis from carbon dioxide (CO₂) and nitrate (NO₃⁻) offers a sustainable alternative to the traditional Bosch-Meiser method. However, the complexity of intermediates in co-reduction hampers simultaneous improvement in urea yield and Faradaic efficiency (FE). Herein, we developed a Cu/Cu₂O Mott–Schottky catalyst with nanoscale rectifying heterointerfaces through precise controllable in situ electroreduction of Cu₂O nanowires, achieving notable FE (32.6–47.0 %) and substantial yields (6.08–30.4 μmol h⁻¹ cm⁻²) across a broad range of ultralow applied potentials (0 to −0.3 V vs. RHE). Operando synchrotron radiation-Fourier transform infrared spectroscopy (SR-FTIR) confirmed the formation of *CO intermediates and C−N bonds, subsequently density functional theory (DFT) calculations deciphered that the Cu/Cu₂O rectifying heterointerface modulated *CO adsorption, significantly enhancing subsequent C−N coupling dynamics between *CO and *NOH intermediates. This work not only provides a groundbreaking and advanced pathway for C−N coupling, but also offers deep insights into copper-based heterointerface catalysts for urea synthesis.