The proton conductivity of the layered hydrates, WO3•2H2O and WO3•H2O, was investigated at 273 to 423K under various water-vapor pressures. The dihydrate exhibited conductivities as high as 0.007S/cm at 423K. The conductivity stayed at this level until the compound began to decompose. The activation energy for conductivity at 323 to 423K was equal to 0.36eV. At lower temperatures, the conductivity depended very strongly upon the water pressure. The activation energy here was much smaller (0.15eV), and was typical of the surface-water mechanism. In the case of the monohydrate, the temperature-dependence of the conductivity was uniform; with an activation energy of 0.13eV at 298 to 423K. Its conductivity at 423K was about an order of magnitude lower than that of the dihydrate.

Proton Conductivity of Tungsten Trioxide Hydrates at Intermediate Temperatures. Y.M.Li, M.Hibino, M.Miyayama, T.Kudo: Solid State Ionics, 2000, 134[3-4], 271-9