Eseoghene Jeroro, Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Room 311A Towne Building, 220 South and 33rd Street, Philadelphia, PA 19104 and John M. Vohs, Chemical and Biomolecular Engineering, University of Pennsylvania, Room 311A Towne Building, 220 South and 33rd Street, Philadelphia, PA 19104.
Methanol and ethanol have been proposed as potential bio-renewable sources of hydrogen. The use of alcohols, however, as a source of H2 or for H2 storage requires stable reforming catalysts that have high activity at low temperatures. Pd on ZnO is one potential catalyst for this reaction since it exhibits an unusually high selectivity (>95%) for the production of CO2 and H2 from methanol, in spite of the fact that bulk Pd exhibits nearly 100 % selectivity for the dehydrogenation of CH3OH to CO and H2 under typical SRM conditions. Pd/ZnO and Co/ZnO also exhibit high selectivity to CO2 for the steam reforming of ethanol. Recent results from our group have illustrated how alloying the Pd with Zn affects the dehydrogenation of CH3OH and CH2O on Pd/ZnO catalysts. In this talk we will give an overview of this work and also describe our more recent TPD and HREELS studies of the adsorption of C2H5OH and CH3CHO on model catalysts consisting of sub-monolayer amounts of Zn on Pd(111). Results for the adsorption of these molecules on Co(0001) and Zn/Co(0001) model catalysts will also be presented. Overall, these studies provide new fundamental insight into how Zn alters the reactivity of Pd and Co for the dehydrogenation of C2H5OH and is useful in elucidating the mechanism of the steam reforming of ethanol on these catalysts.