Abstract Understanding and uncovering really catalytic active‐sites during electrocatalysis is vital for carbon–nitrogen coupling reaction to synthesize urea. Here, we report a Copper (Cu) single‐atom catalyst (Cu‐N 3 SAs) with a Cu–N 3 coordination structure for the electrochemical coreduction of CO 2 and NO 3 − into urea. The in situ X‐ray absorption spectroscopy (XAS) reveals that the Cu–N 3 configured single‐sites undergo electrochemically structural reconstruction to form N 2 –Cu–Cu–N 2 dual‐sites in Cu–N 3 SAs, exhibiting efficient urea synthesis performance. The in‐situ spectroscopy combined with mass spectrometry confirms that the initial C–N coupling reaction involves the formation of *CONH from *CO and *NH intermediates generated via the coreduction of CO 2 and NO 3 − on the N 2 –Cu–Cu–N 2 dual‐sites. The in‐situ electrochemical formed Cu dual‐sites not only enhance the adsorption of *CO, but also facilitates the multi‐electron transfer processes with lowered energy barrier for the formation of *CONH intermediates.
Liu et al. (Tue,) studied this question.