Changes of Composition and Structure of Pt-Ru/C Catalyst in the Methanol Electro-Oxidation Process

In this paper, the changes in the composition and Structure of Pt-Ru/C catalyst in the course of the methanol electrooxidation were Studied by cyclic voltammetry (CV), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that the Surface layer of Pt-Ru/C catalyst. was Ru-rich structure and possessed excellent synergistic effect for methanol electrocoxidation in the early stage of CV scan. While the cycling number increased from 1 to 35, the peak potential of methanol oxidation gradually shifted to the high potential, which was attributed to decrease of the synergistic effect owing to the dissolution of Ru atoms in the surface of Pt-Ru/C catalyst. When further increasing the cycling number to 36 similar to 80, the Ru content tends to be stable. However, the particles size of Pt-Ru nanoparticles gradually increased due to the moving and relocation of surface Pt atom, which resulted in the decrease of electrocatalytical activity of the catalyst for methanol oxidation.