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  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    title: Catalysis and surface reactivity studied by pulsed field desorption mass spectrometry
  name:
    name part: Chuah, Gaik-Khuan.
    role:
      role term: creator
  name:
    name part: Cocke, David L.
    role:
      role term: degree supervisor.
  name:
    name part: Anthony, R. G.
    role:
      role term: degree committee member.
  name:
    name part: Gingerich, K. A.
    role:
      role term: degree committee member.
  name:
    name part: Lunsford, J. H.
    role:
      role term: degree committee member.
  name:
    name part: Texas A & M University
    role:
      role term: degree granting institution.
  type of resource: text
  genre: bibliography
  genre: Academic theses
  origin info:
    place:
      place term: xx
    date issued: 1987
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: print
    extent: xii, 135 leaves : illustrations ; 29 cm
  abstract: Pulsed field desorption mass spectrometry (PFDMS) is used to investigate the early stages of ruthenium oxidation and the decomposition of methanol over ruthenium, rhodium, palladium and copper. Various oxides are identified during ruthenium oxidation at O₂ pressures below 10⁻³ Pa. RuO₂ is formed on the clean metal at 700 K but on a preoxidized surface, ionic species of RuO₃ and RuO₄ are detected. The presence of clusters ions -- Ru₂O₄⁺, Ru₂O₅⁺ and Ru₂O₆⁺ -- suggests nucleation of RuO₂ and RuO₃. The mobilities of the latter oxides are proved in a specially designed experiment. The catalytic decomposition of methanol over ruthenium, rhodium and palladium leads to carbon monoxide and hydrogen. Secondary reactions of carbon monoxide yield metal subcarbonyls. PFDMS allows the direct observation of the reaction intermediates, CH₃O, CH₂O and CHO. On ruthenium, at temperatures below 460 K, high intensities of CH₃⁺ (from CH₃O) are observed, indicating that the decomposition of adsorbed methoxy is inhibited by the final product, adsorbed carbon monoxide. At temperatures above 460 K, surface coverage of absorbed carbon monoxide is lowered by thermal desorption during the reaction interval. Methanol readily decomposes at empty sites and the intensities of the detected intermediates are small. Hence, the reaction is desorption rate limited below 460 K. The decomposition on rhodium shows a similar behavior as on ruthenium. Adsorbed carbon monoxide thermally desorbs at temperatures [greater than or equal to] 500 K. Below this temperature, the overall reaction is limited by the thermal desorption of CO[subscript ad]. A model is postulated for methanol decomposition based on stepwise H-abstraction. The slow step in the overall reaction is the decomposition of the methoxy. The influence of an electric field on the decomposition reaction is studied by applying a steady field during the reaction time between the pulses. At a field strength of about 4 V/nm, the intensities of CHO⁺, CH₂O…
  note: Typescript (photocopy).
  note: Vita.
  note: Ph. D. in Chemistry Texas A & M University 1987
  note: Includes bibliographical references (leaves 119-128).
  subject:
    topic: Metals
    topic: Surfaces
  subject:
    topic: Surface chemistry
  subject:
    topic: Field desorption mass spectrometry
  subject:
    topic: Major chemistry
  identifier: http://proxy.library.tamu.edu/login
  related item:
    location:
      url: http://proxy.library.tamu.edu/login
  record info:
    record content source: TXA
    record creation date: 881220
    record change date: 20200904152404.0
    record identifier: in00000741203
    language of cataloging:
      language term: eng