Lewis acid sites incorporation promotes CO2 electroreduction to multicarbon oxygenates over B-CuO nanotubes

Herein, we designed a C2+-producing catalyst by incorporating Lewis acid boron dopant into porous copper oxides nanotubes (B-CuO NTs) via a convenient electrospinning−calcination method. The B-CuO NTs catalyst achieved a 60.5% C2+ Faraday efficiency (FE) including 47% of ethanol, a 4-fold increase over CuO in a flow cell at − 0.6 V vs reversible hydrogen electrode (RHE). In situ characterizations demonstrate that the strong ability for *CO adsorption on B-CuO NTs facilitates the hydrogenation to the *CHO intermediate and promotes the C-C coupling further to *OCCHO intermediate via the proton-coupled electron transfer reactions. Theoretically calculations demonstrate that B doping induced polarized charge redistribution could suppress the *CHO transfer to C1 products by reducing the energy barrier for further OC-CHO coupling. This work provides a comprehensive understanding of Lewis acid B doping effect on regulating the C-C coupling pathway and improving the C2 selectivity.