AVS 50th International Symposium
    Surface Science Tuesday Sessions
       Session SS1-TuM

Paper SS1-TuM2
Reactions of Aliphatic Alcohols on WO@sub3@(001) Surfaces

Tuesday, November 4, 2003, 8:40 am, Room 327

Session: Catalysis II: Hydrocarbons at Metal Surfaces
Presenter: S. Ma, University of Maine
Authors: B.G. Frederick, University of Maine
S. Ma, University of Maine
Correspondent: Click to Email
Interactions of ethanol and isopropanol with WO@sub3@(001) thin film surfaces, epitaxially grown on a sapphire substrate, were studied with calibrated thermal desorption spectroscopy (CTDS). The reactivity of reduced and oxidized WO@sub3@ surfaces, as characterized by XPS and UPS, were compared in order to understand the surface structure dependence. Coverage dependent desorption spectra show that alcohol molecules diffuse rapidly on the WO@sub3@ thin film surfaces. Ethanol and isopropanol desorb molecularly between 200 and 450 K with evolution of water. The remaining alkoxy intermediates decompose via @BETA@-H elimination, followed by C-O bond scission, to produce ethylene and propylene, respectively. We suggest that diffusion and competition between reaction rates of dehydroxylation vs. associative molecular desorption of alcohol control the alkoxy coverage that determines the selectivity toward alkene under these low coverage conditions.