High performance membrane-electrode assemblies with ultra-low Pt loading for proton exchange membrane fuel cells

High performance membrane-electrode assemblies (MEAs) with ultra-low Pt loadings have been prepared by a modified thin film method. The method involves a mixing of the carbon supported Pt catalyst with Nafion solution without adding any additional organic solvents and a processing of the MEAs at lower temperatures (<100 °C). The MEAs thus fabricated show high Pt utilization efficiency and power density. The best performance is achieved with a Pt loading of 0.1 mg/cm2 using a 20 wt.% Pt/C. Moreover, the performance loss is not significant even when the Pt loading is reduced further to as low as 0.05 mg/cm2. A scanning electron microscopic analysis reveals that the thin catalyst layers are uniform with a good interfacial continuity between the membrane and the electrodes.