Regensburg 2010 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

O: Fachverband Oberflächenphysik

O 27: Metal subtrates: Adsorption of O and/or H

O 27.2: Talk

Tuesday, March 23, 2010, 10:45–11:00, H42

The interaction of oxygen with AgPd/Pd(111) surface alloys - A case study for ensemble effects on bimetallic surfaces — •Thomas Diemant, Joachim Bansmann, and R. Jürgen Behm — Institute of Surface Chemistry and Catalysis, Ulm University, D-89069 Ulm, Germany

AgPd/Pd(111) surface alloys, which consist of a reactive and an inert metal, represent an ideal test case for the study of ensemble effects on bimetallic surfaces. The structural properties of these planar model systems (surface contents and atom distribution) are accessible by high-resolution scanning tunnelling microscopy (STM), while the chemical/adsorption properties can be studied by a combination of temperature-programmed desorption (TPD) and vibrational spectroscopy, such as high-resolution electron energy loss spectroscopy (HREELS). We have used this approach to correlate the structural properties of structurally well-defined AgPd/Pd(111) surface alloys to their oxygen adsorption behaviour. The modification of the oxygen adsorption properties can be attributed predominantly to ensemble effects. Ligand effects only play a minor role. The results will be compared to findings on the interaction of CO with these surface alloys.

[1] Yunsheng Ma et al., Surf. Sci. 603 (2009) 1046.