Potential-induced synthesis of cavity Cu2O/Cu nanocubes for enhanced electroreduced CO2 to C2+ products

Electrochemical reduction reaction of CO 2 (CO 2 RR) to C 1 and C 2 products can be achieved on Cu-based electrocatalysts. C 2 products exhibit higher energy density and economic value compared to C 1 products, making them more desirable as reduction products. However, the production of C 2 products on pure Cu catalysts involves multi-step proton-coupled electron transfer and C–C coupling steps, which are kinetically slow and result in poor catalytic activity and selectivity for the products. The cavity nanocubes Cu 2 O(0.13-AA), Cu 2 O(0.10-AA) and Cu 2 O(0.15-AA) catalysts were synthesized via wet chemical reduction by adjusting the concentration of the reducing agent. The electrochemical pre-reduction method was used to obtain Cu 2 O/Cu(0.13-AA), Cu 2 O/Cu(0.10-AA) and Cu 2 O/Cu(0.15-AA) catalysts for CO 2 RR. Cu 2 O/Cu(0.13 M-AA) catalyst achieves the high Faradaic efficiency (FE) of 39.98% for C 2 H 4 and 54.76% for C 2 products (C 2 H 4 , C 2 H 6 , and C 2 H 5 OH), with significant inhibition of the hydrogen evolution reaction. In situ Raman experiments demonstrate that the cavity structure of the nanocubes enhances the local concentration of *CO intermediates, thereby promoting the C–C coupling process and improving the selectivity of CO 2 reduction to C 2 products.