PtRu/C catalyst slurry preparation for large-scale decal transfer with high performance of proton exchange membrane fuel cells.

The large-area membrane-electrode assembly (MEA) has been fabricated using the decal transfer method with a methanol (MeOH)-based PtRu/C catalyst slurry. The stability of slurry dispersion is important when using a large-area decal transfer method to ensure the integrity of the electrode. In order to prepare stable and well dispersed catalyst slurry, a suitable solvent for the PtRu/C catalyst should be selected. We considered the physical properties of various organic solvents, including ionomer solubility, dielectric constant, and catalyst particle surface physical properties. We found that the MeOH-based PtRu/C slurry dispersion showed the best stability and dispersibility of catalyst-ionomer agglomerates. It was also confirmed that the MeOH-based slurry has the most suitable characteristics for coating the slurry on the substrate film. The decal technique-based MEA using this slurry showed excellent performance when compared with the spray method-based MEA. Furthermore, the large-area PtRu/C MEA with an active area of 51.84 cm was fabricated and excellent performance was realized even when a reforming gas was used.