Efficient Urea Electrosynthesis on a Cu <sub>3</sub> Molecular Catalyst with Dynamically Adaptive Intercopper Spacings
Mengqiu Xu, Yuanyuan Xue, Zhengzheng Liu, Ximeng Lv, Qing Han, Gengfeng Zheng
Abstract
Electrocatalytic urea synthesis from carbon monoxide (CO) and nitrate ions (NO 3 – ) represents a promising alternative to the conventional energy-intensive industrial methods, while this approach is strongly limited by the kinetically sluggish C–N coupling process and the competing side reactions. Herein, we report a trinuclear-copper molecular catalyst (denoted as Cu 3 -flex) that can enable dynamic and self-adaptive intercopper spacings among those triangular-shaped Cu 3 adjacent sites upon the binding of two *CO and one *NO 3 – . The dynamic variation of the intercopper spacings induced by the bridged *CO adsorption allows us to promote the first C–N coupling of *CO and *N to form the key *NCO intermediate, as well as the subsequent capturing of another *NO 3 – and the second C–N coupling to produce urea. The Cu 3 -flex catalyst exhibited a high urea electrosynthesis performance for the coreduction of CO and NO 3 –, including a urea production rate of 122 mmol·g cat. –1 ·h –1, a Faradaic efficiency of 69%, and a notable electrochemical stability of >125 h.