Effect of Solution Dielectric Constant on the Preparation of Gas Diffusion Electrode Reaction Layer for the Oxygen Reduction Reaction

This study explored the impact of solvent dielectric constant on the catalyst layer of proton exchange membrane fuel cell (PEMFC) cathodes during the oxygen reduction reaction. Electrochemical analyses were conducted at 25ºC in 2.0 M H2SO4 on electrodes that had been prepared with the same Nafion and Pt loadings, but different solvent dielectric constants for ink preparation of the catalyst layer. A Nafion loading of 0.5 mg cm-2 and Pt loading of 1 mg cm-2 were employed for all electrodes. The findings of the research revealed that the dielectric constant of the ink utilized for preparing the gas diffusion electrode reaction layer has an impact on the electrode's performance for the oxygen reduction reaction. This effect was evident in both the kinetics parameters linked to the oxygen reduction reaction and the physical characteristics of the electrode surface. In the preparation of the reaction layer, an optimal electrode performance result of 4.2 was achieved in relation to the dielectric constant.