Sulfated zirconia–Nafion composite membranes for higher temperature direct methanol fuel cells

A sulfated zirconia/Nafion®115 nanocomposite membrane is prepared by ion-exchange of zirconium ions into the Nafion followed by precipitation of sulphated ZrO2 by treatment in 5 M H2SO4 at 80 °C. The incorporation of sulfated zirconia increases water uptake by the Nafion membrane, and importantly, more water is absorbed than by an unmodified membrane at high temperatures. The proton conductivity of the composite membrane is evaluated and compared with that of an unmodified Nafion®115 membrane. The nanocomposite membrane experiences a smaller decrease in proton conductivity than the Nafion®115 membrane at high temperatures.