Effect of Molybdenum Doping on Oxygen Permeation Properties and Chemical Stability of SrCo_0.8Fe_0.2O_3-δ

The phase composition, microstructure, thermal expansion coefficients, oxygen permeation properties and chemical stability of SrCo_0.7Fe_0.2Mo_0.1O_3-δ (SCFM) were investigated and compared with those of SrCo_0.8Fe_0.2O_3-δ (SCF). Single phase SCFM was successfully pre-pared by a combined EDTA-citric method. SCFM shows a lower thermal expansion coefficient (24×10^-6～29×10^-6/K) than SCF between 500 and 1050 oC, indicating a more stable structure. SCFM shows a high oxygen permeation flux, although the oxygen flux of SCFM decreases slightly because of Mo dopant. Furthermore, it was demonstrated that the doping of Mo in SCF can prevent the order-disorder transition and improves the chemical stability to CO₂.