Unleashing High Yield Urea Production by Pulse Electrodeposition of Bi/Cu via Co-reduction of N2 and CO2

The expanding agricultural practices rely on carbon- and energy-intensive Bosch–Meiser processes for urea synthesis. Alternatively, electrochemical coupling of CO2 and N2 is emerging as a sustainable approach. Unfortunately, the high energy barrier for N2 and CO2 cracking for C–N bond coupling limits the urea synthesis efficiency. Herein, we have electrodeposited Bi on Cu foil via triple pulse voltage, and the fabricated Bi(0.01 V)@Cu electrode demonstrates a high yield rate of 646 μg h–1 mg–1cat. of urea with 70.7% Faradaic efficiency at −0.45 V vs RHE. The isotopic labeling experiments assert that the produced urea is solely from the dissolved CO2 and N2 gases. More importantly, we have utilized in situ electrochemical Raman spectroscopy and Fourier transform infrared (FTIR) measurements to monitor the real-time formation of urea, further supported by a microelectrochemical approach using a Pt-microelectrode and the results were verified by density functional theory (DFT) analysis. Moving a step forward, plant growth and flowering upon addition of extracted urea have been demonstrated for practical application.