Nafion/ZrSPP composite membrane for high temperature operation of proton exchange membrane fuel cells

To extend the proton conductivity of Nafion at high temperatures above 100 °C zirconium sulphophenyl phosphate (ZrSPP) particles were used as a solid proton conductor and hygroscopic material. ZrSPP was obtained by the reaction of Zr4+ ion and m-sulphophenyl phosphonic (SPP) acid with a stoichiometric ratio P/Zr = 2. The synthesis of ZrSPP was confirmed by phosphonate (P–O) stretching band, assigned at 900–1300 cm−1 in FT-IR spectra. Nafion/ZrSPP composite membranes almost maintained the maximum conductivity of Nafion even at 110 °C when hydrated at 98% RH. The Nafion/ZrSPP membrane showed four times better cell performance than recast Nafion at 100 °C.