Characterization of Nafion®/Zirconium Sulphophenyl Phosphate Nanocomposite Membrane for Direct Methanol Fuel Cells

Layered structure zirconium sulphophenyl phosphate (ZrSPP) was prepared from the precipitation of Zr4+ ion and m-sulphophenyl phosphonic (SPP) acid at a mole ratio of P to Zr = 2.0. The reflective index measurement indicated that the methanol permeability of unmodified Nafion 117 was 2.3 x 10(-6) cm(2)/s at RT while that of the Nafion (R)/ZrSPP membrane (similar to 50 mu m thick) decreased to 6.5 x 10(-7) cm(2)/s. Nafion (R)/ZrSPP (10 wt%) nanocomposite membranes delivered constant power output 104 mW/cm(2) @ 0.4 V under 1 M MeOH/dry air at 70 degrees C even in the wide range of air stoichiometry from 1.5 to 3.0.