Sputter-deposited ultra-low catalyst loadings for PEM fuel cells

Sputter-deposited Pt thin film layers are employed as catalyst material for polymer electrolyte membrane (PEM) fuel cells. An ultra-low catalyst loading of 5 μ g cm−2 platinum results in a maximum power density of 124-132 mW cm−2 depending on the gas diffusion layer substrate when feeding H2/O2 at ambient temperature and pressure. By using the sputter deposition process less catalyst is needed for comparable cell performance to contemporary standard electrodes loaded with 1 mg cm−2 Pt that have been used for reference. Catalyst layers sputter-deposited onto different porous electrodes are investigated with respect to their effect on characteristic fuel cell performance which improves by 8% after adding chromium or palladium thin film layers.