Alloying effects of Pd and Ni on the catalysis of the oxidation of dry CH4 in solid oxide fuel cells

The mechanisms of Ni, Pd and Pd-Ni catalysts in a solid oxide fuel cell (SOFC) were studied to clarify the alloying effects of Pd and Ni on the catalysis for the oxidation of CH4 fuel. Pd-Ni and Pd catalysts loaded on a composite anode of La0.8Sr0.2CrO3 (LSCr) and Ce0.8Sm0.2O1.9 (SDC) show catalytic activity for the oxidation of CH4. The impedance study for these anodes clearly suggests a difference between the reaction mechanisms on the Pd-Ni/and the Pd/LSCr-SDC anodes. The dominant reaction path for the methane activation seems to be a non-electrochemical process on the Pd-Ni catalyst, whereas the activation of CH4 over the Pd catalyst occurs only on electrochemically active sites. (C) 2009 Elsevier B.V. All rights reserved.