The preparation and O permeation properties of novel composites of Ce0.9Sm0.1O1.95–xvol%Mn(1.5−0.5y)Co(1+0.5y)Ni0.5O4 (CSO–xMCNO; 5 ≤ x ≤ 25; 0 ≤ y ≤ 1.0) were investigated. The composites were prepared by the Pechini process to obtain fine microstructures. The composites fired at 1300C for 2h were found to consist of Ce0.9Sm0.1O1.95 and two different spinel-type oxides. The O flux density of 0.3mm-thick CSO–15MCNO with y = 1.0 was found to be 1.1 and 7.5μmol/cm2s at 1000C under He (20sccm)/air and Ar–10%CH4 (100 scm)/air gradients, respectively. CSO–25MCNO with a larger amount of spinel-type phases exhibited an O flux density of 6.2μmol/cm2s and CO selectivity of 72% at 1000C without a conventional reforming catalyst. In addition, Ce0.9Sm0.1O1.95–15vol%MnFe2O4 (CSO–15MFO) membranes were prepared by using a tape-casting technique. As a result of the optimization of slurry composition, a crack-free dense membrane with dimensions of 5cm x 5cm was successfully prepared after sintering at 1300C for 2h. For the tape-cast 133μm-thick membrane, an O flux density of 9.5μmol/cm2s was attained at 1000C.

Oxygen Permeation and Methane Reforming Properties of Ceria-Based Composite Membranes. H.Takamura, T.Kobayashi, T.Kasahara, A.Kamegawa, M.Okada: Journal of Alloys and Compounds, 2006, 408-412, 1084-9