Enhanced electrochemical CO2 reduction to C2+ products on porous CuCo bimetallic electrodes via prereduction in alkaline solution

Abstract

The electrochemical CO₂ reduction reaction (ECR) offers a promising pathway for achieving a carbon-neutral economy. In this study, CuCo bimetallic electrodes were optimized via a prereduction surface strategy in an alkaline solution, resulting in a significantly rougher surface, the generation of more active sites, reduced charge transfer resistance, and an increased concentration of K⁺ ions on the electrode surface. The electrode treated with this strategy exhibited an outstanding C₂₊ faradaic efficiency exceeding 37% at −0.45 V vs. RHE, with an n-propanol faradaic efficiency of more than 10% at a remarkably low electrolysis potential (−0.85 V vs. RHE). In situ electrochemical attenuated total reflectance surface-enhanced Fourier transform infrared absorption spectroscopy (ATR-SEIRAS) analysis was further employed to reveal the mechanism of enhanced ECR and suppressed hydrogen evolution reaction (HER). The innovative surface strategy and operando characterization provided an invaluable method for designing advanced electrodes and deep insights into the mechanisms driving ECR toward C₂₊ products.