Dresden 2009 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

O: Fachverband Oberflächenphysik

O 45: Heterogeneous catalysis

O 45.1: Vortrag

Donnerstag, 26. März 2009, 10:30–10:45, SCH A215

Interaction of CO₂ and CH₄ with MgO/CeO₂/Cu(111) and Pt/CeO₂/Cu(111) model catalyst surfaces — •Yaroslava Lykhach, Thorsten Staudt, Michael P. A. Lorenz, Regine Streber, Andreas Bayer, Hans-Peter Steinrück, and Jörg Libuda — Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 3, D-91058 Erlangen

We have studied the interaction of CO₂ and CH₄ with CeO₂ based model catalyst. Toward this aim, we employ epitaxially grown CeO₂ films on Cu(111) as well-ordered model supports [1]. Morphology and growth of the deposited films were characterized by means of STM and LEED. The CeO₂/Cu(111) substrates were modified by deposition of MgO or Pt. The reaction behaviour of CO₂ on MgO/CeO₂/Cu(111) was investigated by XPS. The interaction of CH₄ was studied on CeO₂/Cu(111) and Pt/CeO₂/Cu(111) in supersonic beam assisted experiments. Different carbonaceous species formed on the surfaces were monitored by XPS as a function of exposure, sample temperature and MgO or Pt particle sizes. Upon stepwise annealing removal of carbon is observed. While the Pt particles are recovered, significant reduction of CeO₂ substrate is observed at temperatures significantly lower than for clean Pt/CeO₂/Cu(111). This indicates active participation of CeO₂ in removal of carbonaceous species via reverse-spillover of oxygen from the CeO₂ support to Pt.

[1] V. Matolin et al., Thin Solid Films 516 (2008) 6120-6124.