• About
  • Policies
  • What is openaccess
  • Library
  • Contact
Advanced search
      View Item 
      •   BUIR Home
      • Scholarly Publications
      • Faculty of Science
      • Department of Chemistry
      • View Item
      •   BUIR Home
      • Scholarly Publications
      • Faculty of Science
      • Department of Chemistry
      • View Item
      JavaScript is disabled for your browser. Some features of this site may not work without it.

      Gold catalysts supported on ceria doped by rare earth metals for water gas shift reaction: influence of the preparation method

      Thumbnail
      View / Download
      1.8 Mb
      Author
      Andreeva, D.
      Ivanov, I.
      Ilieva, L.
      Abrashev, M. V.
      Zanella, R.
      Sobczak, J. W.
      Lisowski, W.
      Kantcheva, M.
      Avdeev, G.
      Petrov, K.
      Date
      2009
      Source Title
      Applied Catalysis A: General
      Print ISSN
      0926-860X
      Electronic ISSN
      1873-3875
      Volume
      357
      Issue
      2
      Pages
      159 - 169
      Language
      English
      Type
      Article
      Item Usage Stats
      134
      views
      112
      downloads
      Abstract
      Gold catalysts based on ceria, doped by various RE metals (La, Sm, Gd, Yb, Y) were studied. The influence of the preparation methods on structure, properties and catalytic activity in the WGS reaction was investigated. The catalysts' supports were prepared using two different methods: co-precipitation (CP) and mechanochemical activation (MA). The catalysts were tested in a wide temperature interval without and after reactivation. All samples were characterized using a combination of X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), Raman spectroscopy (RS) and X-ray photoelectron spectroscopy (XPS) and TPR. It was found that the catalytic activity of MA catalysts is higher than CP ones. The gold catalysts based on ceria doped by Yb and Sm exhibited the highest activity. After reactivation in air the MA samples almost kept the WGS activity same, while the CP catalysts increased it. The catalysts of a single- and double-phase structure are formed as a result of CP and MA preparation, respectively. There are no big differences in the gold particles size (2-3 nm) depending on dopants and on the preparation techniques. The RS spectra analysis indicates that most probably the oxygen vacancies are adjacent to Me3+ dopant and the ceria structure seems to be better ordered than in the case of alumina as a dopant. There is no distinct correlation between reducibility and WGS activity. The XPS analysis disclose positively charged gold particles in addition to metallic gold within a surface region of fresh samples and only metallic gold on the samples after catalytic processing. There is no simple correlation between the concentration of Ce3+ in the samples and their WGS activity.
      Keywords
      Ceria doped by Yb, Sm, Gd, Y, La
      HRTEM
      TPR
      WGS
      XPS
      XRD
      Catalysis
      Catalyst activity
      Cerium
      Cerium compounds
      Chemical shift
      Doping (additives)
      Electrochemical sensors
      Gadolinium
      Gold
      High resolution transmission electron microscopy
      Inert gases
      Lanthanum
      Nonferrous metals
      Oxygen
      Oxygen vacancies
      Rapid solidification
      Spectrum analysis
      X ray diffraction analysis
      X ray photoelectron spectroscopy
      Ytterbium
      Yttrium alloys
      Gold catalysts
      Raman
      Catalyst supports
      Permalink
      http://hdl.handle.net/11693/22776
      Published Version (Please cite this version)
      http://dx.doi.org/10.1016/j.apcata.2009.01.027
      Collections
      • Department of Chemistry 632
      Show full item record

      Browse

      All of BUIRCommunities & CollectionsTitlesAuthorsAdvisorsBy Issue DateKeywordsTypeDepartmentsThis CollectionTitlesAuthorsAdvisorsBy Issue DateKeywordsTypeDepartments

      My Account

      Login

      Statistics

      View Usage StatisticsView Google Analytics Statistics

      Bilkent University

      If you have trouble accessing this page and need to request an alternate format, contact the site administrator. Phone: (312) 290 1771
      © Bilkent University - Library IT

      Contact Us | Send Feedback | Off-Campus Access | Admin | Privacy