Pt-based High Performance Catalysts For Fuel Cell

Proton exchange membrane fuel cell using methanol and formic acid as reactantshas been considered as one of the dominant green energy sources It is studied focusedand extensively, due to its high energy conversion rate, fast response speed, lowoperating temperature, environmental friendly, and other advantages. However, thefuel cell anode catalyst suffers from a few of problems, such as the low catalyticactivity, easily poisoned by CO, high cost of the noble metal catalysts. In order toimprove its commercialization, two effective methods including the addition ofcocatalyst and/or using novel high-performance supporting substrate can be adopted toalleviate these problems. In this paper, we prepared several new anode catalysts ofPt/CeO2-ZrO2/MWCNT, Pt-Fe/RGO, and Pt-Fe/NG, and demonstrated their excellentelectrochemical properties. The main research contents are shown as follows:1. Pt/CeO2-ZrO2/MWCNTs catalyst was prepared via hydrothermal method usingmulti-walled carbon nanotubes (MWCNT, purity>95%) as supporting materials andCeO2-ZrO2as cocatalyst. TEM result showed that CeO2and ZrO2nanoparticles weredensely loaded on the surface of MWCNT and Pt nanoparticles dispersed. When usedas anode catalysts for methanol electroxidation, it exhibited higher methanolelectrochemical catalytic activity, improved CO poisoning tolerance, and betterstability than those of the Pt/MWCNTs, which should be attributed to the addition ofCeO2-ZrO2cocatalysts and the good substrate of MWCNTs.2. We synthesized reduced graphene oxide (RGO) supported FePt alloynanoparticles as high-performance electrocatalysts for methanol and formic acidoxidation. The microstructure, composition and morphology of the sample aresystematically characterized by X-ray diffraction, fourier transform infraredspectroscopy, scanning electron microscope, transmission electron microscope, energydispersive spectroscopy and Raman spectroscopy. The electrocatalytic oxidation tests reveal that, in comparison with pure Pt nanoparticles supported on RGO sheets, theFePt nanoalloys anchored RGO sheets deliver remarkably enhanced electrocatalyticperformance on FA/methanol oxidation, improved tolerance to CO poisoning, andsuperior catalytic durability.3. In this chapter, a two-step synthesis method, which consists of hydrothermalreaction and solid state reduction by H2, is employed to prepare a series ofPtxFe100-x/N-doped graphene nanocomposites with controllable Pt:Fe compositions.The morphology, microstructure, and composition of the samples are systematicallycharacterized by transmission electron microscope, scanning electron microscope,energy dispersive spectroscopy, powder X-ray diffraction and Raman spectroscopy.The as-obtained products are employed as catalysts for FA/methanol electrooxidation.The effects of nitrogen doping and alloying with Fe on the improvement of catalyticperformance are explored. And the synergistic interaction between them is alsoobtained. Additionally, the composition sensitive catalytic activity and stability ofthese catalysts for formic acid electrooxidation are probed and the optimum Pt:Fe ratiois presented.