Oxygen- and hydrogen-permeation measurements on-mixed conducting SrFeCo0.5Oy ceramic membrane material

The SrFeCo0.5Oy System combines high electronic/ionic conductivity with appreciable oxygen permeability at elevated temperatures. This system has potential use in high-temperature electrochemical applications such as solid oxide fuel cells, batteries, sensors, and oxygen separation membranes. Dense ceramic membranes of SrFeCo0.5Oy are prepared by pressing a ceramic powder prepared by using a sol-gel combustion technique. Oxygen and hydrogen permeation at high temperature on this material are studied. Measurements are conducted using a time-dependent permeation method at the temperature in the range of 1073-1273 K with oxygen- and hydrogen-driving pressures in the range (3 x 10(2))-(1 x 10(5)) Pa (300-1000 mbar). The maximum oxygen-permeated flux at 1273 K is 6.5 x 10(-3) Mol m(-2) s(-1). The activation energies for the O-2-permeation fluxes and diffusivities are 240 and 194 kJ/mol, respectively. Due to the high fragility, the high temperature for the measurements and the high oxygen permeation through such material, a special membrane holder, and compression sealing system have been designed and realized for the permeation apparatus. (C) 2007 Elsevier Ltd. All rights reserved.