Stabilized Triple-Phase Interface at CF4 Plasma Bombarded Cu Gas Diffusion Electrode for CO2-to-C2H4 Valorization

Cu-based gas diffusion electrodes (GDEs) hold the potential to produce carbon-neutral fuels and value-added chemicals from CO 2 greenhouse gas at substantial current densities, yet they are challenged by the sluggish reaction kinetics toward C 2+ product production and the fierce competition of H 2 evolution from electrowetted/flooded catalyst layers. Herein, we develop a roughened hydrophobic Cu/PTFE GDE via CF 4 plasma bombardment and demonstrate its effectiveness in facilitating CO 2 -to-C 2 H 4 valorization. Online electrochemical mass spectrometry reveals that the enhanced C 2 H 4 electrosynthesis is correlated with the increased rates of CO 2 consumption and CO utilization, as well as a reduction in H 2 generation upon CF x modification. Molecular dynamics simulations highlight the significant promotional effect of electrolyte management sustaining a high local [CO 2 ]/[H 2 O] ratio near the CF x –Cu surface, where the improved C–C coupling kinetics is attributable to the abundant Cu δ+ sites adjacent to surface-bonded fluorocarbons with electron-withdrawing character.