Regensburg 2013 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 67: Competition for the Gerhard Ertl Young Investigator Award
O 67.3: Vortrag
Donnerstag, 14. März 2013, 11:30–12:00, H45
Comparative Density Functional Theory Study of Acetaldehyde Hydrodeoxygenation Mechanisms on Ru and RuO2 Catalysts — •Lars Grabow — Chemical and Biomolecular Engineering, University of Houston, 4800 Calhoun Rd., S222, Houston, TX 77204-4004
The hydrodeoxygenation (HDO) mechanism of acetaldehyde, a surrogate molecule for the over 400 different oxygenated species in biomass-derived pyrolysis oil, is presented for the Ru(0001) and RuO2(110) surfaces based on Density Functional Theory results. Under typical HDO reaction conditions, the thermodynamic phase diagram indicates that the RuO2(110) surface is partially reduced and terminated by OH-groups on the bridging O-sites. Further reduction and creation of a surface O-vacancy site are necessary to create an active site for acetaldehyde adsorption through its terminal O-atom and selective conversion to ethylene. In contrast, acetaldehyde is more easily activated on Ru(0001), but metallic Ru favors C-C bond over C-O bond scission which leads to the unwanted formation of CO and CH4. Given the higher C-O bond scission selectivity on the metal-oxide, a rapid prediction method for surface phase diagrams and equilibrium O-vacancy concentrations of other rutile(110) surfaces is developed. In combination with a more detailed understanding of the HDO mechanism on metal and metal-oxide catalysts this model can be used for the development of new and efficient catalysts that can lead to an increased utilization of biofuels.