Studies On Anodic Catalytic Materials Of Direct Methanol Fuel Cell(DMFC)

Direct methanol fuel cell (DMFC) use cheap methanol as the fuel. It does not need the fuel reforming equipment. Its operating temperature is low.The fuel source is abundant and is easy to store and to transport. Therefore, it is an ideal power for mobile electronic equipments and electric automobiles. However, it is difficult for commercialization due to high cost and low catalytic activity of noble metal Pt and PtRu alloys anodes. So it is an important research topic to reduce the dosage and increase the activity and utilization of noble metal Pt. In this paper, nano-dispersed Pt/PANI-G and Pt-Ni-Zr/PANI-G anodic catalysts were prepared successfully via the microemulsion method, which use polyaniline-graphite compound material as carrier.(1)Conducting polyaniline-graphite composites was synthesized by microemulsion and the structure and performance of the carrier was characterized by FT-IR TG XRD TEM conducting and electrochemical tests. The results shows that the carrier has preferable conductivity when the graphite amount is 10wt.%. there are bonds between graphite and polyaniline. Polyaniline-graphite composites has bigger surface area than polyaniline.(2)Pt(20wt%)/PANI-G and Pt-Ni-Zr/PANI-G electrocatalyst was prepared by A to B and A+B microemulsion and the catalysts was characterized by XRD TEM XPS and so on. The results indicate that the catalyst prepared by A+B microemulsion has better structure and performance. The particle size of catalyst is influenced remarkably by theωvalues of mictoemulsion and the concentration of precursors. When theωis 8.71 and the concentration is 0.0192mol/L, the particle size of the catalyst is about 4.0nm. Pt is 0 +2 and +4 value. The electrochemical surface area is about 15.99m²/g. The peak current density and peak potential of the catalyst for methanol electrooxidation is 282.04μA·㎝^-2 and 0.603V respectively. The metals in Pt-Ni-Zr/PANI-G form good alloyed structure. The metals are 0 +2 value and so on in the catalyst. The particle size of Pt is about 3nm.The Pt in Pt₁₁Ni₆Zr₃/PANI-G has big electrochemical activity surface areas and the catalyst has high heat stabilization. The catalyst also has better electrocatalytic activity for methanol, which become better with the increasing of the concentration and temperature of methanol. At room temperature, the peak current density and peak potential of Pt₁₁Ni₆Zr₃/PANI-G in 1mol/L CH₃OH + 0.5mol/L H2SO4 solution is 440.94μA·㎝^-2 and 0.539V respectively.