Electron-enriched Cu active sites arising from an atomic-scale Mott–Schottky analogy in SnCu nanoalloy catalyst, exhibited quadruple synergism: enhanced CO₂ and NO₃ ⁻ co-adsorption, elevated *CO surface coverage, accelerated *NHO-*CO coupling, and concurrent HER suppression, collectively achieving a twofold enhancement in urea yield compared to pristine Cu.

Abstract

Electrocatalytic urea synthesis from CO₂ and NO₃ ⁻ offers a sustainable strategy to address environmental challenges and growing urea demand. However, current systems suffer inefficient C-N coupling due to poor selectivity toward critical C/N-intermediates. Herein, we engineered atomic-scale Mott–Schottky analogy in SnCu nanoalloy to create electron-enriched Cu sites, enabling remarkable urea production through quadruple synergy. Sn₂Cu delivered exceptional urea yield (28.9 mmol h⁻¹ g_cat. ⁻¹) with 46.7% Faradaic efficiency (FE) in H-cell, while demonstrating practical potential with superior catalytic performance (yield: 72.6 mmol h⁻¹ g_cat. ⁻¹, FE: 41.3%, stability: 60 h) at −0.52 V in flow cell. In-situ synchrotron radiation-Fourier transform infrared spectroscopy and theoretical calculations revealed electron-enriched Cu active sites enhanced CO₂/NO₃ ⁻ co-adsorption and *CO coverage, while steering reaction pathway toward *CO-*NHO coupling and suppressing hydrogen evolution, thereby reducing rate-determining step energy barrier and prioritizing C-N coupling. This work develops a structure–adsorption-reactivity framework, providing fundamental guidance for advanced urea electrocatalyst design.