Berlin 2008 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
O: Fachverband Oberflächenphysik
O 62: Metal Substrates: Adsorption of Inorganic Molecules
O 62.12: Talk
Thursday, February 28, 2008, 12:15–12:30, MA 042
Interaction of CO and H2 with Zn/ZnO modified Pd(111) surfaces — •Markus Kratzer1, Anton Tamtögl1, Jörg Killmann1, Robert Schennach1, Adolf Winkler1, Gunter Weirum1, and Svetlozar Surnev2 — 1Institute of Solid State Physics, Graz University of Technology — 2Department of Physics, Karl-Franzens University Graz
Due to its increased use in methanol reforming the Zn/Pd and ZnO/Pd system came to the fore of surface science. Especially, the interaction with CO and hydrogen with these surfaces is of specific importance. In this work the adsorption/desorption kinetics of CO and H2 on Zn and ZnO thin film covered Pd(111) was studied using TPD, LEED, AES and STM. TPD, LEED and AES results show that the ZnO modified palladium surfaces undergo a change in the surface configuration during CO and H2 desorption due to reduction of the ZnO layer. In case of CO-TPD temperatures up to 650 K are required, which additionally lead to the formation of a ZnPd alloy. In the literature one can find UPS measurements as well as DFT based calculations that point out that ZnPd alloys should have similar electronic properties as the Cu(111) surface [1]. Indeed, CO desorption on Zn covered Pd(111) shows a similar low temperature desorption peak at 220 K as measured on Cu-surfaces [2].
This work was supported by the Austrian Science Fund: Project Nr. P20016 and P19198.
[1] A. Bayer et.al. Surface Science, 600 (2006) 78
[2] S. Vollmer et.al. Catalysis Letters 77 (2001) 97