关键词: Nafion膜, 聚吡咯, 甲醇渗透, 质子电导率

Abstract: Polypyrrole modified Nafion membranes（PPy/Nafion）are prepared by FeCl3 oxidation methods. In addition，Co is chemically reduced on the cathode side of the modified membrane to prepare Co-PPy/Nafion membrane. The thermal stability，methanol penetrability and proton conductivity of Nafion membranes and the modified membranes are studied by TG，CV and AC impedance. Results show that PPy/Nafion and Co-PPy/Nafion have better thermal stability and low methanol permeation than Nafion membrance. Membrane-electrode-assemblies（MEAs）for a DMFC are fabricated by using Nafion membranes，PPy/Nafion and Co-PPy/Nafion respectively，with PtRu/C as an anode catalyst and Pt/C as a cathode catalyst. It is found that the modification of Nafion membrane with Co-polypyrrole can improve the performance of MEA to a great extent when the cell is operated at higher methanol concentrations and higher discharging current densities.

Key words: Nafion membrane, polypyrrole, methanol permeability, proton conductivity