Five-fold twinned copper nanowires for electrochemical CO2 reduction with enhanced C2 product selectivity and stability

This study investigates copper nanowires with fivefold twinned structures (t-CuNWs) as catalysts for the electrochemical reduction of CO2 (CO2RR) in a zero-gap flow cell with 1 M KOH as anolyte. The t-CuNWs, with surfaces enclosed by (100) facets, were selected for their enhanced CO adsorption strength, which promotes C–C coupling—a key pathway toward multi-carbon (C2+) products. Additionally, the entangled t-CuNWs exhibits enhanced hydrophobicity when compared to commercial Cu nanoparticles (CuNPs), which can reduce flooding issues and contribute to high stability during electrochemical operation. These characteristics distinguish t-CuNWs from CuNPs in terms of activity and stability. The t-CuNWs exhibited ~ 40% C2H4 faradic efficiency (FE) for more than 4 hours under a current density of 100 mA/cm2, while commercial CuNPs exhibited ~ 20% C2H4 FE for less than 4 hours under the same condition. These findings highlight the potential of (100) faceted t-CuNWs for efficient and durable C2+ product formation in CO2RR with facet engineering and hydrophobicity control.