X-ray photoelectron spectroscopic studies of Ba0.5Sr0.5Co0.8Fe0.2O3-delta cathode for solid oxide fuel cells

The Ba0.5Sr0.5Co0.8Fe0.2O3-delta (BSCF) cathode for solid oxide fuel cell has been prepared by glycine-nitrate combustion process. Crystal structure and chemical state of BSCF have been studied by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). XRD pattern indicates that a single cubic perovskite phase of BSCF oxide is successfully obtained after calcination at 850 degrees C for 2 h. XPS results show there exists a little amount of SrCO3 in the surface of BSCF. Co2p spectra indicate that some Co3+ ions have changed into Co4+ ions to maintain the electrical neutrality. O1s spectra present that adsorbed oxygen species appear in the surface BSCF oxide. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.