Conduction and H permeation in dense SrCe0.95Tm0.05O3 membranes were studied at 600 to 950C. Measurements showed that the temperature dependence of the conductivity obeyed the Arrhenius relationship in O, air, N and 10%H/He atmospheres. The presence of water vapour lowered both the conductivity and the activation energies in oxidizing atmospheres; thus suggesting mixed proton-electron conduction. The H permeation flux increased with temperature at lower temperatures, and tended to level off at higher temperatures. At a given temperature, the H flux increased with the upstream H partial pressure and downstream O partial pressure. The H flux also increased with decreasing membrane thickness; thus indicating that bulk diffusion was the rate-limiting step in H permeation through thick membranes. Fluxes as high as 3 x 10-8/cm2s were detected at 900C (1.6mm-thick membrane) when 10%H/He and air were used as the feed and sweeping gases, respectively.

Electrical Conduction and Hydrogen Permeation through Mixed Proton-Electron Conducting Strontium Cerate Membranes. X.Qi, Y.S.Lin: Solid State Ionics, 2000, 130[1-2], 149-56