Oxygen- and hydrogen-permeation measurements on-mixed conducting SrFeCo 0.5O y ceramic membrane material

Abstract

The SrFeCo 0.5O y 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 SrFeCo 0.5O y 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 (3×10 2)–(1×10 5) Pa (300–1000 mbar). The maximum oxygen-permeated flux at 1273 K is 6.5×10 −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.