Single-Atom\nRh<sub>1</sub> Alloyed Co for Urea Electrosynthesis\nfrom CO<sub>2</sub> and NO<sub>3</sub><sup>–</sup>

Single-atom Rh<sub>1</sub> alloyed Co (Rh<sub>1</sub>Co) is explored\nas an efficient catalyst for urea electrosynthesis via coelectrolysis\nof CO<sub>2</sub> and NO<sub>3</sub><sup>–</sup> (UECN). Theoretical\ncalculations and in situ spectroscopic measurements unravel the synergetic\neffect of Co and Rh<sub>1</sub> in promoting the UECN process, where\nthe Rh<sub>1</sub> site activates NO<sub>3</sub><sup>–</sup> to form *NH<sub>2</sub>, while the Co site activates CO<sub>2</sub> to form *CO. The formed *CO then desorbs from the Co site and transfers\nto the Rh<sub>1</sub> site, followed by continuous C–N coupling\nwith *NH<sub>2</sub> formed on the Rh<sub>1</sub> site to synthesize\nurea. Remarkably, Rh<sub>1</sub>Co assembled in a flow cell delivers\nthe exceptional urea yield rate of 24.9 mmol h<sup>–1</sup> g<sup>–1</sup> and Faradaic efficiency of 51.1%, outperforming\nmost previously reported UECN catalysts.