Single-Atom Rh₁ Alloyed Co for Urea Electrosynthesis from CO₂ and NO₃

Single-atom Rh₁ alloyed Co (Rh₁Co) is explored as an efficient catalyst for urea electrosynthesis via coelectrolysis of CO₂ and NO₃^- (UECN). Theoretical calculations and in situ spectroscopic measurements unravel the synergetic effect of Co and Rh₁ in promoting the UECN process, where the Rh₁ site activates NO₃^- to form *NH₂, while the Co site activates CO₂ to form *CO. The formed *CO then desorbs from the Co site and transfers to the Rh₁ site, followed by continuous C-N coupling with *NH₂ formed on the Rh₁ site to synthesize urea. Remarkably, Rh₁Co assembled in a flow cell delivers the exceptional urea yield rate of 24.9 mmol h^-1 g^-1 and Faradaic efficiency of 51.1%, outperforming most previously reported UECN catalysts.