Stabilized Triple-Phase Interface at CF<sub>4</sub> Plasma Bombarded Cu Gas Diffusion Electrode for CO<sub>2</sub>-to-C<sub>2</sub>H<sub>4</sub> Valorization.

Shen, Peng; Ji, Ziyu; Ye, Ke; Ge, Xiaolin; Xu, Tongwen; Xie, Pengfei; Cai, Wen-Bin; Jiang, Kun · Nano Lett · 2025

basic_science · Level V

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Abstract

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