Operando X-Ray Diffraction Analysis of a Microtubular La_0.6Sr_0.4Co_0.2Fe_0.8O_{3 – δ} Membrane

The high-temperature performance of a microtubular (MT) La_0.6Sr_0.4Co_0.2Fe_0.8O_{3 – δ} (LSCF) membrane is studied by the operando high-temperature X-ray diffraction method. The LSCF powders are synthesized and the microtubular membranes are fabricated with the use of the phase inversion technique. The microtubular membranes are subjected to the direct resistive heating by electric current. It is shown that the outer surface of the MT membrane has the structure close to that of the LSCF powder at the same oxygen concentration in the gas phase not only when the feed gas is delivered outside the membrane but also when its external surface is blown around by pure helium at a rate of 200 mL/min.