Boosting electrosynthesis of urea from N2 and CO2 by defective Cu-Bi

Electrosynthesis of urea from N2 and CO2 molecules is of immense significance but has so far been plagued by the lack of a universal design principle to guide the search for new catalysts. Herein, as exemplified by the Cu-Bi catalyst, our findings revealed that the defective Cu-Bi catalyst could offer a maximum urea concentration of 0.45 ± 0.06 mg L−1 and the largest faradaic efficiency of 8.7% ± 1.7% at −0.4 V (versus reversible hydrogen electrode [RHE]), exhibiting outstanding activity in contrast to monometallic (Cu and Bi) and bimetallic (Cu-Bi mixture and intact Cu-Bi) catalysts. Moreover, the evidence from isotope tracing experiments, in situ Raman spectroscopy, and density functional theory (DFT) calculations suggested that it is a promising strategy for the co-reduction of N2 and CO2 by defective Cu-Bi catalysts, switching on a light to the application of defects in electrosynthesis of urea.