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The mixed perovskite type oxides with nominal formula LaTi _0.5 Mg _0.5-x Pd _x O ₃ , (0 ≤ x ≤ 0.10) were prepared by anneling the ethanol solution of precursor in nitrogen flow at 1200°C. X-ray powder diffraction (XRPD) analysis shows that the orthorhombic perovskite structure was found in all investigated samples. However, at least a part of palladium is not incorporated into perovskite structure and remains as separate phase, which is reduced to Pd ⁰ at 1200°C. X-ray photoelectron spectroscopy (XPS) reveled the presence of Pd ²⁺ , which indicate a reoxidation of Pd ⁰ in the surface layers during cooling. The Pd content in the samples has a small influence on the methane oxidation activity below the temperature of 500°C. At temperatures higher than 500°C, the methane oxidation activity of the sample with x = 0.05 exceeds the activity of the sample with x = 0.10. The sharp increase of methane oxidation activity over the sample with lower content of palladium at about 500°C was ascribed to the higher dispersion of PdO and Pd ⁰ phases. Thus, the higher contribution of lattice oxygen and possible local change in oxidation state of palladium can be a reason for the enhanced activity. Contrary to the supported Pd/Al ₂ O ₃ catalyst, the incorporation of palladium into perovskite matrix and interaction of PdO-Pd ⁰ benefits the activity of smaller particles at higher reaction temperatures. © 2004 Elsevier B.V.. All rights reserved.