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dc.contributor.authorAndonova, S. M.en_US
dc.contributor.authorŞentürk, G. S.en_US
dc.contributor.authorKayhan, E.en_US
dc.contributor.authorOzensoy, E.en_US
dc.date.accessioned2016-02-08T10:03:52Z
dc.date.available2016-02-08T10:03:52Z
dc.date.issued2009en_US
dc.identifier.issn1932-7447
dc.identifier.urihttp://hdl.handle.net/11693/22717
dc.description.abstractA ternary oxide-based NO* storage material in the form of BaOZTiO2Zy-Al2O3 was synthesized and characterized. Thermally induced structural changes occurring on the surfaces of the TiO2Zy-Al2O3 and BaOZ TiO 2Zy-Al2O3 systems were studied in a comparative manner within 300-1273 K via X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, and BET surface area analysis. The surface acidity of the studied oxide systems was also investigated via pyridine adsorption monitored by in-situ Fourier transform infrared (FTIR) spectroscopy. BaO/TiO2γ-Al 2O3 ternary oxide was synthesized by incorporating different loadings of (8-20 wt %) BaO onto the TiO2/γ Al 2O3 support material, which was originally prepared using the sol-gel method. In the TiO2Zy-Al2O3 binary oxide support material, anatase phase exhibited a relatively high thermal stability at T < 1073 K. The presence of TiO2 domains on the surface of the alumina particles was found to alter the surface acidity of alumina by providing new medium-strength Lewis acid sites. SEMZEDX results indicate that in the BaO/TiO2γ-Al2O3 system, TiO2 domains present a significant affinity toward BaO and/or Ba(NO3) 2 resulting in a strong Ti-Ba interaction and the formation of overlapping domains on the surface. The presence of TiO2 also leads to a decrease in the decomposition temperature of the Ba(N03) 2 phase with respect to the Ti-free Ba(N03) 2ZyAl2O3 system. Such a destabilization is likely to occur due to a weaker interaction between Ba(N03) 2 and y-Al203 domains in the ternary oxide as well as due to the change in the surface acidity in the presence of TiO 2. At relatively high temperatures (e.g., 873-1273 K) formation of complex structures in the form of BaTiO3, Ba1.23Al 2.46Ti5.54O16, BaTiO5, andor Ba x:AlyTizOn., were also observed. © 2009 American Chemical Society.en_US
dc.language.isoEnglishen_US
dc.source.titleJournal of Physical Chemistry Cen_US
dc.relation.isversionofhttp://dx.doi.org/10.1021/jp9005026en_US
dc.subjectAlumina particlesen_US
dc.subjectAnatase phaseen_US
dc.subjectBET surface areaen_US
dc.subjectBinary oxidesen_US
dc.subjectComplex structureen_US
dc.subjectDecomposition temperatureen_US
dc.subjectEnergy dispersive x-rayen_US
dc.subjectHigh temperatureen_US
dc.subjectHigh thermal stabilityen_US
dc.subjectIn-situen_US
dc.subjectLewis acid siteen_US
dc.subjectOxide systemsen_US
dc.subjectPyridine adsorptionen_US
dc.subjectSEMen_US
dc.subjectSol-gel methodsen_US
dc.subjectStorage systemsen_US
dc.subjectStructural changeen_US
dc.subjectSupport materialsen_US
dc.subjectSurface acidityen_US
dc.subjectTernary oxidesen_US
dc.subjectThermally induceden_US
dc.subjectTiOen_US
dc.subjectAdsorptionen_US
dc.subjectAluminumen_US
dc.subjectBariumen_US
dc.subjectFourier transform infrared spectroscopyen_US
dc.subjectGelationen_US
dc.subjectRaman spectroscopyen_US
dc.subjectScanning electron microscopyen_US
dc.subjectSol-gel processen_US
dc.subjectSurface analysisen_US
dc.subjectSurfacesen_US
dc.subjectTitanium dioxideen_US
dc.subjectTitanium oxidesen_US
dc.subjectX ray diffractionen_US
dc.subjectX ray diffraction analysisen_US
dc.subjectBarium compoundsen_US
dc.titleNature of the Ti-Ba interactions on the BaO/TiO2/Al 2O3 NOx storage systemen_US
dc.typeArticleen_US
dc.departmentDepartment of Chemistry
dc.departmentUNAM - Institute of Materials Science and Nanotechnology
dc.citation.spage11014en_US
dc.citation.epage11026en_US
dc.citation.volumeNumber113en_US
dc.citation.issueNumber25en_US
dc.identifier.doi10.1021/jp9005026en_US


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