Ionic-liquid-modified electrocatalysts supported on nanoporous polycarbonate membranes as efficient gas diffusion electrodes for micro fuel cell applications

We report a new gas diffusion electrode (GDE) architecture based on nanometric porous platinum films modified with ionic liquids (ILs) and supported on nanoporous polycarbonate membranes (PCMs), and evaluate its performance as oxygen-reducing cathode. Thin Pt films were deposited by sputtering and impregnated with 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, which uniformly covered the membrane without blocking pores. As oxygen-reducing cathodes operating with pure O 2 , these GDEs are capable to sustain steady-state current densities of around −0.4 A cm −2 , with stable operation for at least 1 h. The influence of IL loading on performance and stability is critically analyzed, showing that excessive IL amounts hinder oxygen transport, while deficient IL quantities lead to instability due to flooding. Exploratory tests for hydrogen oxidation also demonstrate an outstanding performance of these GDEs as hydrogen anodes. This proof-of-concept study establishes PCMs as effective supports for IL-based GDEs and highlights their potential for integration into micro fuel cells.