Abstract
According to a recently proposed mechanism, the silver-catalyzed industrial synthesis of ethylene oxide (EO) involves adsorbed SO4. The O atoms that are added to the ethylene molecules to give EO originate from SO4, which may solve the long-standing question about the active oxygen species in this reaction. Here, we report a low-energy electron diffraction structure analysis of an ordered phase of SO4 on the Ag(111) surface, forming a (7 x root 3)rect structure and containing the oxygen species that before had been spectroscopically identified on the active catalyst. Using I(V) data from a low-energy electron microscope and an input model from density functional theory, the complex structure could be solved. It contains SO4 moieties on a reconstructed Ag(111) surface in which all four O atoms bind to Ag atoms. In the proposed ethylene epoxide reaction model, the structure represents the parent phase from which the active SO4 phase is formed by a lifting of the reconstruction.
Item Type: | Journal article |
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Faculties: | Geosciences > Department of Earth and Environmental Sciences |
Subjects: | 500 Science > 550 Earth sciences and geology |
ISSN: | 1932-7447 |
Language: | English |
Item ID: | 67901 |
Date Deposited: | 19. Jul 2019, 12:23 |
Last Modified: | 04. Nov 2020, 13:50 |