Anhydrous Proton Conducting Hybrid Membrane Electrolytes for High Temperature (>100°C) Proton Exchange Membrane Fuel Cells

Anhydrous proton conducting hybrid membranes were prepared by the sol-gel process with trimethoxysilane (TMOS)/trimethoxypropylsilane (TMPS)/triethyl phosphate (TEP) and BMIMBF 4 ionic liquid as precursors.The Fourier transform infrared and NMR measurements have shown good chemical stability of these hybrid membranes.Average pore sizes and specific surface areas were investigated by the Brunauer-Emmett-Teller method.Thermogravimetric analysis and differential thermal analysis measurements confirmed that the hybrid membranes were thermally stable up to 250 C. Maximum anhydrous conductivity of 6.4 Â 10 À3 S/cm was obtained for 40 wt % ionic liquid based hybrid membrane, at 150 C, with a hydrogen permeability value of 0.8 Â 10 À12 mol/cm s Pa.