Scalable fabrication of multi-layered Cu-based electrodes via solvent-free method for the selective electrochemical conversion of CO2 to C2+ products

Abstract

In the research field of CO₂ electroreduction, gas diffusion electrodes (GDEs) are predominantly manufactured through solvent-based processes. Meanwhile, the solvent-free method has gained heightened attention due to its potential to reduce operational and production expenses, while considering ecological aspects such as solvent evaporation, circulation, and waste treatment. Drawing from its successful applications in other fields, we have specifically developed a solvent-free manufacturing method to produce multi-layered Cu-based GDEs for CO₂ electroreduction. The procedure is compatible with industrial production lines, specifically through a roll-to-roll process. By evaluating the interplay between production parameters and electrochemical performance of GDEs via various characterization methods, key factors, i.e., hydrophobicity, gas permeability, thickness, and pore size, were adjusted and applied to achieve a highly selective GDE towards C₂₊ products (alcohols and ethylene) at industrial relevant currents up to 300 mA cm⁻² (ethylene ∼40%, ethanol ∼10%, n-propanol ∼15%).