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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The Oxidation of Methanol on Cr₂O₃ (101̅2) Single Crystal Surfaces

Mensch, Michael W. 04 April 2003 (has links)
The reaction of methanol with the nearly-stoichiometric and oxygen-terminated surfaces of Cr₂O₃ (101̅2) was studied using thermal desorption spectroscopy and x-ray photoelectron spectroscopy. Dissociative adsorption of methanol occurs on the nearly-stoichiometric surface and is attributed to the presence of cation/anion site-pairs. An array of products including CH₄, CH₂O, CO, CO₂, and H₂ are produced above 550 K on the nearly-stoichiometric surface. Monolayer coverage of methanol yields a 58% conversion to products. Of these products, selectivity to CO is the highest (41%), followed by CH₂O (28%), CH₄ (24%), and CO₂ (7%). At higher temperatures methoxides reversibly undergo dehydrogenation and nucleophilic from lattice oxygen to form dioxymethylene. Hydrogenation of methoxides leads to the formation of CH₄ and CH₃OH above 550 K. Formate is formed as a surface intermediate by reversible dehydrogenation of dioxymethylene. Formaldehyde is produced via C-O bond cleavage of dioxymethylene, and the decomposition of formate yields CO, CO₂, and H₂. The oxygen-terminated surface is unreactive for methanol dissociation due cation site blocking by terminal chromyl oxygen. / Master of Science

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