Methane oxidation over SOFC anodes with nanocrystalline ceria-based phases

The electrocatalytic performance of cermet anodes comprising Pt and nanocrystalline ceria-based components, Pt-modified Ce0.45Zr0.45-La0.1O2-delta (CZLO) and Ce0.8Gd0.2O2-delta (CGO), was evaluated for the oxidation of dry CH4 in a SOFC-type reactor with zirconia-based electrolyte. At temperatures above 1100 K, CZLO-containing cermet exhibits a high activity towards the partial oxidation of methane, probably promoted by instability of the cubic fluorite lattice. For the stoichiometric O-2:CH4 ratio equal to 0.5, the CO yield over CZLO/Pt anode is 73% with 54% conversion at 1173 K. Further increase in the CO selectivity and CH4 conversion, up to 84% and 87% respectively, can be achieved by incorporating Pt-modified CZLO catalyst at the reactor outlet. (c) 2006 Elsevier B.V. All rights reserved.