Electrocatalytic CO 2 -to-C 2+ with Ampere-Level Current on Heteroatom-Engineered Copper via Tuning *CO Intermediate Coverage

An ampere-level current density of CO 2 electrolysis is critical to realize the industrial production of multicarbon (C 2+ ) fuels. However, under such a large current density, the poor CO intermediate (*CO) coverage on the catalyst surface induces the competitive hydrogen evolution reaction, which hinders CO 2 reduction reaction (CO 2 RR). Herein, we report reliable ampere-level CO 2 -to-C 2+ electrolysis by heteroatom engineering on Cu catalysts. The Cu-based compounds with heteroatom (N, P, S, O) are electrochemically reduced to heteroatom-derived Cu with significant structural reconstruction under CO 2 RR conditions. It is found that N-engineered Cu (N–Cu) catalyst exhibits the best CO 2 -to-C 2+ productivity with a remarkable Faradaic efficiency of 73.7% under −1100 mA cm –2 and an energy efficiency of 37.2% under −900 mA cm –2 . Particularly, it achieves a C 2+ partial current density of −909 mA cm –2 at −1.15 V versus reversible hydrogen electrode, which outperforms most reported Cu-based catalysts. In situ spectroscopy indicates that heteroatom engineering adjusts *CO adsorption on Cu surface and alters the local H proton consumption in solution. Density functional theory studies confirm that the high adsorption strength of *CO on N–Cu results from the depressed HER and promoted *CO adsorption on both bridge and atop sites of Cu, which greatly reduces the energy barrier for C–C coupling.