The present study focuses on the development of environmentally friendly gas diffusion electrodes (GDE) as part of the BMBF project DisCO₂very. A primary goal is to replace polytetrafluorethylene (PTFE) in conventional GDEs, which are crucial in various electrochemical processes, with fluorine-free binders to enhance sustainability. The study investigates the impact of the binder on the electrochemical CO₂ reduction (eCO₂R) process, which converts CO₂ into valuable chemicals, thereby contributing to a future fossil-free chemical industry.

The research is based on a silver-based GDE utilizing PTFE as a benchmark, as developed by Moussallem et al. PTFE’s hydrophobic properties prevent excessive electrolyte penetration into the GDE. To replicate these characteristics without PTFE, the incorporation of superhydrophobic methyl MQ silicone resin-coated SiO₂ nanoparticles is explored to augment hydrophobicity. The results indicate that the PTFE-free GDE can achieve a comparable short-term maximum performance to the PTFE reference. However, a significant decline in performance is noted over time, attributed to the degradation of the incorporated particles.

The findings suggest that functionalized particles can mitigate the inherent lower hydrophobicity of fluorine-free binders, potentially leading to a viable PTFE-free GDE. For industrial applications, it is critical to address the degradation of GDEs, and strategies to enhance stability through different materials will be essential. Overall, this work aims to pave the way for more sustainable electrochemical systems and materials.