Lanthanum chromite based catalysts for oxidation of methane directly on SOFC anodes

Catalytic properties of substituted lanthanum chromites were investigated f or 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, CO2 r eforming 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 LaCrO3 lattice. Three different catalytic behaviors were observed depe nding on the substituents. The Ni-substituted powders showed the highest ac tivity toward CH4. Ni substitution showed also interesting H2O and CO2 refo rming activities. For all catalysts, except in the case of Fe-substituted L aCrO3, only a small amount of carbon was detected on the surface (1 similar to3 monolayers). Among the investigated A-site and B-site substitutents, S r and Ni were found to be the most active and the most suitable substituten ts for the LaCrO3 SOFC anode purpose. (C) 2001 Academic Press.