Surface characterization and catalytic properties of perovskite type solid oxide solutions, La0.8Sr0.2BO3 (B = Cr, Mn, Fe, Co or Y)

The surface compositions of La0.8Sr0.2BO3 (B = Cr, Mn, Fe, Co or Y) were investigated by X-ray photoelectron spectroscopy (XPS). Among the five solid oxide solutions, the yttrium showed the highest concentration in the surface atomic ratio [B-ion(La + Sr)]. Furthermore, the O1s spectra characteristics of yttrium perovskite are found to be different from those of the other solid solutions with the peak shifted to higher binding energy value. The electrical conductivity of La0.8Sr0.2CrO3 and La0.8Sr0.2YO3 were also measured as a function of temperature in air. The Eσ values for conduction were found to be 0.12 and 0.72 eV respectively. The conductivity data correlated well with the catalytic activity of these solid solutions for the oxidation of methane.