AVS 60th International Symposium and Exhibition
    Surface Science Friday Sessions
       Session SS-FrM

Paper SS-FrM1
Oxidation of Pd Supported on Au(111) and Single Crystal ZnO Supports

Friday, November 1, 2013, 8:20 am, Room 201 A

Session: Oxides and Semiconductors: Structure and Reactivity
Presenter: J. Lallo, University of South Florida
Authors: J. Lallo, University of South Florida
M. Batzill, University of South Florida
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Supported palladium catalysts are involved in many important catalytic reactions, such as steam reforming of methanol and methane combustion. Palladium oxide has been discovered to play an important role in these reactions, and the conditions and mechanisms involved for PdO formation are of great interest. In this work we investigate the role of substrates in palladium oxidation. Thin films of Pd, < 10nm, are grown on Au(111) and different crystallographic orientations of ZnO substrates under UHV conditions. The films are exposed to high pressure O2 >1x10-3 Torr, at temperatures above 300°C. Post exposure XPS is used to determine the conditions required for stable PdO formation. Angle resolved XPS is used to determine the location of the initial oxidation, either at the film surface or interface. The conditions for oxide formation on single crystal Pd(111) will be compared to the thin Pd-deposits on gold and for different ZnO-terminations. The formation of stable PdO is found to depend on the thickness of the initial Pd film. This study provides insight in the role of the support on the oxidation/reduction of Pd catalysts.