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.