Mechanism of the partial oxidation of ethylene on an Ag surface: Dipped adcluster model study

Hiroshi Nakatsuji, Hiromi Nakai, Keiji Ikeda, Yoko Yamamoto

    Research output: Contribution to journalArticle

    39 Citations (Scopus)

    Abstract

    The partial oxidation of ethylene to ethylene oxide catalyzed by silver is studied by the ab-initio Hartree-Fock and MP2 methods using the dipped adcluster model (DAM). The active species is the superoxide O- 2 which is molecularly adsorbed in a bent end-on geometry on the silver surface. Ethylene reacts with the terminal oxygen atom and the reaction proceeds smoothly without a large barrier to yield ethylene oxide. The complete oxidation of ethylene involving the superoxide is forbidden due to the existence of a large energy barrier. This is one origin of high selectivity. Without the silver surface, the epoxidation reaction is very unfavorable, showing the catalytic activity of the silver surface. The atomically adsorbed oxygen seems not to be selective: it gives both ethylene oxide and complete oxidation products. Therefore, adding to the selectivity due to the superoxide, an overall selectivity larger than 6/7 can be possible. In the process yielding ethylene oxide from atomic oxygen, electron transfer and back-transfer from/to the metal are important processes which can be promoted by both electron donor and acceptor. Detailed electronic mechanisms are clarified and discussed.

    Original languageEnglish
    Pages (from-to)315-333
    Number of pages19
    JournalSurface Science
    Volume384
    Issue number1-3
    Publication statusPublished - 1997 Jul 20

    Fingerprint

    Ethylene Oxide
    ethylene oxide
    Silver
    inorganic peroxides
    Ethylene
    ethylene
    silver
    Superoxides
    Oxidation
    oxidation
    selectivity
    Oxygen
    Oxides
    epoxidation
    Epoxidation
    Electrons
    Energy barriers
    oxygen
    catalytic activity
    oxygen atoms

    Keywords

    • Ab initio Hartree-Fock (HF) and second-order Møller-Plesset (MP2) methods
    • Atomic oxygen
    • Catalytic activity of silver
    • Combustion
    • Dipped adcluster model (DAM)
    • Epoxidation
    • Ethylene oxide
    • Reaction mechanism
    • Superoxide

    ASJC Scopus subject areas

    • Physical and Theoretical Chemistry
    • Condensed Matter Physics
    • Surfaces and Interfaces

    Cite this

    Mechanism of the partial oxidation of ethylene on an Ag surface : Dipped adcluster model study. / Nakatsuji, Hiroshi; Nakai, Hiromi; Ikeda, Keiji; Yamamoto, Yoko.

    In: Surface Science, Vol. 384, No. 1-3, 20.07.1997, p. 315-333.

    Research output: Contribution to journalArticle

    Nakatsuji, H, Nakai, H, Ikeda, K & Yamamoto, Y 1997, 'Mechanism of the partial oxidation of ethylene on an Ag surface: Dipped adcluster model study', Surface Science, vol. 384, no. 1-3, pp. 315-333.
    Nakatsuji, Hiroshi ; Nakai, Hiromi ; Ikeda, Keiji ; Yamamoto, Yoko. / Mechanism of the partial oxidation of ethylene on an Ag surface : Dipped adcluster model study. In: Surface Science. 1997 ; Vol. 384, No. 1-3. pp. 315-333.
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