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Dense planar and tubular oxygen separation membranes of La 0.6Ca 0.4Fe 0.75Co 0.25O 3− δ were investigated as reactors for the partial oxidation (POX) of methane to syngas. Their permeation properties were measured in an air/argon pO 2 gradient as a function of temperature. At 900 °C, the oxygen flux through a 1.26-mm-thick membrane was 0.075  μmol/cm 2·s and through a 0.25-mm-thick tube, 0.24  μmol/cm 2·s. For the POX measurements, a catalyst was added to the membrane and methane was introduced on the argon side. This resulted in a gradual increase of the oxygen flux with increasing concentration of methane, reaching 2  μmol/cm 2·s at 900 °C with pure methane. For the planar reactor, the CO selectivity reached 99% and the CH 4 conversion 75% at 918 °C with pure methane. For the tubular reactor, the CO selectivity and CH 4 conversion were 83 and 99%, respectively, under the same conditions. After 1,400 h of operation in a tubular POX reactor, the membrane was examined revealing phase demixing and local decomposition.

Catalytic properties of substituted lanthanum chromites were investigated for their use as anode materials for direct methane oxidation in solid oxide fuel cell (SOFC) anode materials. Different reaction mixtures were chosen to simulate the various SOFC operating conditions: partial oxidation, CO2reforming by recycling, and H2O reforming. All experiments were performed in methane-rich atmospheres. Alkaline earth elements such as Ca, Sr, and Mg, and first series transition metals—Mn, Fe, Co, and Ni—were substituted into the LaCrO3lattice. Three different catalytic behaviors were observed depending on the substituents. The Ni-substituted powders showed the highest activity toward CH4. Ni substitution showed also interesting H2O and CO2reforming activities. For all catalysts, except in the case of Fe-substituted LaCrO3, only a small amount of carbon was detected on the surface (1∼3 monolayers). Among the investigated A-site and B-site substitutents, Sr and Ni were found to be the most active and the most suitable substitutents for the LaCrO3SOFC anode purpose.