A Homonuclear Ruthenium Dual-Atom Catalyst Enables Efficient Urea Electrosynthesis via Dual Site–Single Site Synergy

Electrocatalytic urea synthesis from CO2 and NO3– (EUCN) offers a sustainable alternative to the traditional route, but it still faces challenges of low C–N coupling efficiency and a sluggish proton-coupled electron transfer process. Herein, a homonuclear Ru dual-atom catalyst (Ru2N6–C) comprising 69.2% Ru2 dual sites and 23.6% Ru1 single sites is developed for efficient EUCN. Operando spectroscopy and mass spectrometry identify *ONCO as the key C–N intermediate, and Ru2N6–C follows a cascade NO3–/CO2 → *NO/*CO → *ONCO → *ONCONO → urea pathway. Further theoretical calculations elucidate the sole role of the Ru1 single site in driving CO2 → *CO, while the Ru2 dual site plays a triple role in driving NO3– → *NO, promoting first/second C–N coupling, and accelerating protonation energetics for urea synthesis. Moreover, by pairing cathodic EUCN with anodic methanol oxidation in a two-electrode electrolyzer, we realize the exceptional Faradaic efficiency of 78.37% and urea yield rate of 102.31 mmol h–1 g–1, while enabling the gram-scale production of high-purity urea.