The Study Of Polypyrrole As DMFC Andoe Catalyst Support

The basic principles and structure, research development of direct methanol fuel cell (DMFC) are summarized in this paper. The research status and preparation methods of anode catalysts are also described in detail. The PPy-C composites were prepared by different methods. The methanol oxidation activity of catalysts supported on PPy-C were investigated. Also, the preparation of PtRu/PPy-C with tartaric acid as reductant or stabilizer was explored.The PPy-C composites were prepared by methods of Template method and in situ chemical oxidative polymerization. Then the Pt nanoparticles were desposited on the composites. The Pt/PPy-C catalysts reduced by tartaric acid have better performance than catalysts made by ethenyl glycol colloid method (EG). The catalyst has the best performance when the amount of PPy in catalyst was 15%(.wt).The performance of catalysts towards methanol oxidation were characterized by cyclic voltammetry and chronoamperometry in 0.5 mol H2SO4 + 0.5 mol CH3OH. The electrochemical surface area (ESA) of catalysts were also tested through cyclic voltammetric curves in a solution of 0.5 mol?L-1 H2SO4. X-ray diffraction(XRD), Transmission electron microscopy (TEM) and energy dispersive analysis of X-ray (EDAX) were used to test physical characterizations of the catalysts. XRD and TEM demonstrated that Pt nanoparticles desposited on PPy-C supporting materials were more uniformly with smaller size. The better CO tolerance ability can be attributed to the interaction of Pt and PPy, which were confirmed by X-ray photoelectron spectroscopy(XPS). The PPy-C supporting material made by in situ chemical oxidative polymerization method has better performance than made by template method.We optimized the preparation of PtRu/C catalyst reduced by tartaric acid. The PtRu/C catalyst prepared by a pH value of 11,a reaction time of 3h has the best performance. PtRu/C catalyst was prepared with Tartaric acid employed for stabilizer and NaBH4 as reductant. The catalyst has better catalytic activity than traditional PtRu/C catalyst. The PtRu/PPy-C catalyst made by the above-mentioned method showed better methanol oxidation activity than PtRu/C. The addition of PPy can keep the catalyst from CO posion, which reduced the catalytic activity of methanol.