The dynamic reversible evolution of vicinal Fe/Cu diatoms and alloy-like Fe–Cu sites during the electrocatalytic reaction allows the initial hydrogenation of CO2 and NO3
− to form key C/N-intermediates, and thermodynamically and kinetically accelerates the subsequent C–N coupling/protonation, enabling the efficient synthesis of urea with ultrahigh yield (2421.2 μg h−1 mg−1) and Faradaic efficiency (70.4%) through a relay electrocatalytic process.
Abstract
The precise construction of dual active sites has been uncovered for the electroreduction of C- and N-based precursors to synthesize urea. However, these strategies often face adsorption scaling constraints and spatial restrictions that hinder C–N coupling, resulting in suboptimal activity and selectivity. Here, we showcase a dynamically reversible evolution between vicinal Fe/Cu diatoms and alloy-like Fe–Cu sites, enabling cascade protonation and efficient C–N coupling. This approach markedly enhances urea electrosynthesis from CO2 and NO3
−, achieving an ultrahigh urea yield of 2421.2 μg h−1 mg−1, Faraday efficiency (FE) of 70.4%, and C-selectivity of 96.7%, surpassing state-of-the-art dual-site electrocatalysts. Operando spectroscopy and theoretical calculations reveal that neighboring Fe/Cu diatoms facilitate the selective adsorption and hydrogenation of NO3
− and CO2 into the key intermediates (*NO and *CO). Furthermore, alloy-like Fe–Cu sites, formed in situ due to declined metal surface free energy driven by electron transfer, facilitate C–N coupling and subsequent protonation to selectively produce urea, while dynamically reverting to vicinal Fe/Cu diatoms. This work provides new insights into the relay catalytic strategy for urea electrosynthesis by modulating the dynamic atomic-scale evolution of active sites.
InfoMat, Volume 7, Issue 11, November 2025. Read More
