rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    non sort: The
    title: partial oxidation of methanol to formaldehyde over molybdenum-containing catalysts
  name:
    name part: Yang, Tsong-Jen.
    role:
      role term: creator
  name:
    name part: Anthony, R. G.
    role:
      role term: degree committee member.
  name:
    name part: Lunsford, J. H.
    role:
      role term: degree supervisor.
  name:
    name part: Rosynek, M. P.
    role:
      role term: degree committee member.
  name:
    name part: Tang, Y. N.
    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: 1982
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: print
    extent: xv, 144 leaves : illustrations ; 29 cm
  abstract: The selective oxidation of methanol to formaldehyde over molybdenum-containing catalysts, such as silica-supported molybdenum oxide and unsupported molybdenum oxides, was studied. This dissertation describes (1) the role of surface oxygen species in stoichiometric reactions at low temperatures in a closed recirculating system, (2) the catalytic reaction of methanol with molybdenum oxide supported on silica gel in a single-pass flow system, and (3) the reaction of methanol with the catalyst in a pulse-reactor. Spectroscopic studies including electron paramagnetic resonance (EPR) spectroscopy, infrared spectroscopy, and x-ray photoelectron spectroscopy (XPS) were used to investigate the surface properties of the catalyst and the nature of the adsorbed species. At low temperatures ((LESSTHEQ) 25(DEGREES)C) O('-) ions reacted with methanol, and at elevated temperatures formaldehyde was desorbed into the gas phase. This reaction, however, was stoichiometric and not catalytic. The superoxide and lattice oxygen ions were much less effective in promoting the low temperature reaction. In the single-pass flow system, the impregnated catalyst prepared from acidic solution with 5.3% Mo by weight was more active than those prepared from basic solution with the same Mo content. Also the variation of activity as a function of Mo loading on the silica-support nearly followed the same trend as expected for the formation of a polymolybdate phase. Thus, this polymolybdate phase, in contrast to isolated molybdenum ions, must constitute the active site for the conversion of methanol to formaldehyde. The results of pulse-flow reactions and XPS experiments show that the active centers also involve molybdenum ions in a lower oxidation state than +6, and Mo('5+) was evident after the catalyst was operated under steady state conditions. Catalytic reactions using unsupported molybdenum oxides as catalysts showed that Mo(,2)O(,5) was quite active. These results indicate that the reaction occur…
  note: "Major subject: Chemistry."
  note: Typescript (photocopy).
  note: Vita.
  note: Ph. D. in Philosophy Texas A & M University 1982
  note: Includes bibliographical references (leaves 136-143).
  subject:
    topic: Catalysts
  subject:
    topic: Methanol
    topic: Reactivity
  subject:
    topic: Molybdenum
    topic: Reactivity
  subject:
    topic: Oxidation
  subject:
    topic: Chemistry
  identifier: http://proxy.library.tamu.edu/login
  identifier: https://hdl.handle.net/1969.1/DISSERTATIONS-380534
  related item:
    location:
      url: http://proxy.library.tamu.edu/login
  related item:
    location:
      url: https://hdl.handle.net/1969.1/DISSERTATIONS-380534
  record info:
    record content source: TXA
    record creation date: 831004
    record change date: 20220104090135.0
    record identifier: in00000370114
    language of cataloging:
      language term: eng