Synthesis and characterization of eletrocatalyst powders for application in PEM fuel cells

The Bonnemann method was chosen to synthesize carbon-supported Pt-Ru-Mo electrocatalyst powders, as this method leads to highly-dispersed nanoparticles with an average particle size of approximately 2 nm. Structural characterization of the resulting catalysts was done by the following techniques: X-rays fluorescence analysis (XFA) and nanosize-energy dispersive X-rays analysis (nano-EDX) to obtain information about noble metal loading and composition as well as X-rays diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) to determine structure, dispersion and crystallite size of the nanoparticles. X-rays photoelectron spectroscopy (XPS) was applied to detect amorphous phases and to determine the oxidation states of Pt, Ru and Mo. The morphology of membrane electrode assemblies, prepared by a spraying technique, was checked by scanning electron microscopy (SEM). For the determination of the electrocatalytic activity E/i curves in single cell arrangements were recorded using both H-2/CO mixtures and methanol as feed gases.