Tuning Intermediates Adsorption and C―N Coupling for Efficient Urea Electrosynthesis Via Doping Ni into Cu

Simultaneous electrochemical reduction of nitrite and carbon dioxide (CO2) under mild reaction conditions offers a new sustainable and low-cost approach for urea synthesis. However, the development of urea electrosynthesis thus far still suffers from low selectivity due to the high energy barrier of *CO formation and the subsequent C & horbar;N coupling. In this work, a highly active dendritic Cu99Ni1 catalyst is developed to enable the highly selective electrosynthesis of urea from co-reduction of nitrite and CO2, reaching a urea Faradaic efficiency (FE) and production rate of 39.8% and 655.4 mu g h(-1) cm(-2), respectively, at -0.7 V versus reversible hydrogen electrode (RHE). In situ Fourier-transform infrared spectroscopy (FT-IR) measurements together with density functional theory (DFT) calculations demonstrate that Ni doping into Cu can significantly enhance the adsorption energetics of the key reaction intermediates and facilitate the C & horbar;N coupling. This work not only provides a new strategy to design efficient electrocatalysts for urea synthesis but also offers deep insights into the mechanism of C & horbar;N coupling during the co-reduction of nitrite and CO2.