Electrosynthesis of Urea on High-Density Ga─Y Dual-Atom Catalyst via Cross-Tuning.

Abstract

Electrochemically converting carbon dioxide (CO₂) and nitrate (NO₃ ^-) into urea via the C─N coupling route offers a sustainable alternative to the traditional industrial urea production technology, but it is still limited by poor yield rate, low Faradaic efficiency, and insufficient coupling kinetics. Herein, a high-density Ga─Y dual-atom catalyst is developed with loading up to 14.1 wt.% of Ga and Y supported on N, P-co-doped carbon substrate (Ga/Y-CNP) for urea electrosynthesis. The catalyst facilitates efficient C─N coupling through co-reduction of CO₂ and NO₃ ^-, resulting in a high urea yield rate of 41.9 mmol h^-1 g^-1 and a Faradaic efficiency of 22.1% at -1.4 V versus the reversible hydrogen electrode. In situ spectroscopy and theoretical calculations reveal that the superior performance is attributed to the cross-tuning between adjacent pair Ga─Y sites, which can mutually optimize their electronic states for facilitating CO₂ reduction to *CO at Ga sites and promoting NO₃ ^- conversion to hydroxylamine (*NH₂OH) at Y sites, followed by spontaneous coupling of *CO and *NH₂OH intermediates at Ga─Y sites to form C─N bonds. This work offers a pioneering strategy to manipulate C─N coupling pathways by cross-tuning active sites to produce high-value-added chemicals.