The O permeation properties of (Ce0.8Pr0.2)O2−δ−xvol%MnFe2O4 composites, with x = 0 to 35, were investigated. The samples were prepared by using the Pechini method. In the case of Ce0.8Pr0.2O2−δ, an O flux-density of 6μmol/cm2s (L = 0.0247cm) and a maximum methane conversion of 50% were attained at 1000C. Unlike composites consisting of Gd-doped CeO2 and MnFe2O4, the O permeability of (Ce0.8Pr0.2)O2−δ–xvol%MnFe2O4 composites was almost constant regardless of the volume fraction of MnFe2O4. However, the optimum volume fraction of MnFe2O4 was found to be 5 to 25 with regard to the chemical and mechanical stabilities in a methane conversion atmosphere. Surface modification of (Ce0.8Gd0.2)O2−δ–15vol%MnFe2O4 composite was performed by using FePt nanoparticles. A catalyst loading of 2.8mg/cm2 on both sides of a 0.3mm-thick (Ce0.8Gd0.2)O2−δ–15vol%MnFe2O4 composite increased the O flux density from 0.30 to 0.76μmol/cm2s in the case of He/air gradients. The effect seemed to be reduced in the case of the high O flux density caused by a high PO2 gradient. Langmuir-Blodgett films of the FePt nanoparticles were successfully prepared on tape-cast (Ce0.8Gd0.2)O2−δ–15vol%MnFe2O4 composite. It was concluded that hydrophobic treatments of the composite surface were critical in achieving a high transfer-ratio for deposition of the Langmuir-Blodgett film.

Oxygen Permeation Properties and Surface Modification of Acceptor-Doped CeO2/MnFe2O4 Composites. H.Takamura, H.Sugai, M.Watanabe, T.Kasahara, A.Kamegawa, M.Okada: Journal of Electroceramics, 2006, 17[2-4], 741-8