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.

Automated summary

A highly active Cu99Ni1 catalyst is developed for the simultaneous electrochemical reduction of nitrite and carbon dioxide to synthesize urea, achieving high selectivity and providing insights into the mechanism of C―N coupling.