Directing the C–N Coupling Pathway Enables Efficient Urea Electrosynthesis

作者：Bihao Hu, Ruihu Lu, Wenlong Wang, Yi-Fan Zhou, Dhayananthan Kalpana Devi Jaswanthi, Zhe Wu, Ziyun Wang, Lei Wang · 发表于：Journal of the American Chemical Society · 年份：2025 · DOI：10.1021/jacs.5c04483 · 被引用次数：82 · 研究领域：Ammonia Synthesis and Nitrogen Reduction、CO2 Reduction Techniques and Catalysts、Electrocatalysts for Energy Conversion

Electrocatalytic synthesis of urea presents a promising approach to closing the artificial nitrogen cycle. However, a major challenge arises from the sluggish C–N coupling step in urea formation compared to other competing electrochemical steps involving nitrate and CO 2 reduction, ultimately limiting the urea selectivity and energy efficiency during the coelectroreduction of nitrate and CO 2 . In this study, we identify *NO 2 as a key intermediate that governs urea activity and selectivity as it can either undergo hydrogenation or couple with CO 2 to form the desired C–N bond. Our theoretical investigations reveal that a decrease in the adsorption energy of *NO 2 on Cu can suppress *NO 2 hydrogenation while enhancing its coupling with CO 2 to favor C–N bond formation. We further discover that doping of Cu with boron increases the energy requirement for *NO 2 hydrogenation and lowers the energy barrier for C–N coupling involved in the formation of *NO 2 CO 2 . Encouragingly, with the synthesized boron-doped Cu catalysts, we achieve a high urea Faradaic efficiency exceeding 80% at a low overpotential of −0.22 V vs the reversible hydrogen electrode, along with a substantial urea production rate of 101.2 μmol h –1 cm –2 . In contrast, the pristine Cu only shows a low urea selectivity (19%) and production rate (<20 μmol h –1 cm –2 ) under identical conditions. Furthermore, a comprehensive life-cycle assessment underscores the significance of abundant nitrate sources for urea elec...