A partial oxidation test was performed using a La0.6Sr0.4Fe0.8Co0.2O3 membrane under surface-limited conditions at 800 to 920C, in a syngas-side atmosphere of CH4 diluted with Ar (100%, 25.6% or 1%). Deposited C was observed at the surface and was revealed to be graphite by means of in situ Raman measurements. It was burnt by O fed through the membrane. Significant decomposition occurred on the air-side surface of the membrane, when tested in a syngas-side atmosphere of 25.6 or 100%. However, this decomposition did not affect the O permeation properties; although it affected the mechanical strength.

Oxygen Permeation Properties and the Stability of La0.6Sr0.4Fe0.8Co0.2O3 Studied by Raman Spectroscopy. F.Iguchi, N.Sata, H.Yugami, H.Takamura: Solid State Ionics, 2006, 177[26-32], 2281-4