摘要 直接甲醇燃料电池(DMFC)以廉价的液体甲醇为燃料，不需要燃料重整设备，运行温度较低，燃料来源丰富，易携带和储存，是便携式电子设备、电动汽车的理想动力源。但其阳极催化剂采用贵金属Pt及PtRu合金，成本高，催化活性低，难以商业化。因此，降低贵金属Pt用量、提高Pt催化剂的活性和利用率，是重要的研究课题。本文采用微乳液法，以聚苯胺-石墨复合材料为载体，成功制备了具有纳米分散性的Pt/PANI-G、Pt-Ni-Zr/ PANI-G阳极催化剂。 (1)通过微乳液法成功合成了聚苯胺-石墨导电高分子催化剂载体，并应用FT-IR、TG、XRD、TEM、导电性和电化学性能测试表征了结构与性能。结果表明石墨含量为10wt%时载体具有较好的导电性能，石墨与聚苯胺之间存在键合作用，聚苯胺-石墨复合材料比聚苯胺具有更大的比表面积。 (2)通过A to B和A+B两种微乳液法成功制备了Pt(20wt%)/PANI-G和Pt-Ni-Zr/ PANI-G电催化剂，采用XRD、TEM、XPS等手段对催化剂进行表征。结果表明A+B微乳液法制得的催化剂具有更好的结构和性能。微乳液的ω、前驱体的浓度对催化剂粒径存在显著的影响，当ω=8.71、前驱体浓度为0.0192mol /L时制得的催化剂Pt粒径4.0nm，以0、+2和+4氧化态存在，电化学活性面积15.99 m2/g，对甲醇的电化学氧化峰电流为282.04 μA•㎝-2、氧化峰电位为0.603V。Pt-Ni-Zr/PANI-G催化剂中金属之间形成较好合金结构，催化剂金属以0、+2等多种氧化态形式存在，Pt粒径大小在3nm左右；Pt11Ni6Zr3/PANI-G催化剂中Pt具有较大的电化学活性面积和较高的热稳定性，对甲醇也有较高的电催化活性且随甲醇浓度和温度的升高而增强，常温时Pt11Ni6Zr3/PANI-G催化剂在1mol/L甲醇+0.5mol/L硫酸溶液中的氧化峰电流为440.94μA•㎝-2、氧化峰电位0.539V。

ABSTRACT 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 the ω values of mictoemulsion and the concentration of precursors. When the ω is 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 282.04 μA•㎝-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.