Dresden 2014 – wissenschaftliches Programm
O 9.9: Vortrag
Montag, 31. März 2014, 12:30–12:45, PHY C 213
Near ambient pressure XPS investigation of the interaction of ethanol with Co/CeO2(111) — •Sandra Krick Calderón1, Óvári László2, Lykhach Yaroslava1, Libuda Jörg1, Erdohelyi Andras3, Papp Christian1, Kiss János2,3, and Steinrück Hans-Peter1 — 1Physikalische Chemie II, University of Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany — 2MTA-SZTE Reaction Kinetics and Surface Chemistry Research Group, H-6720 Szeged, Rerrich Béla tér 1, Hungary — 3Department of Physical Chemistry and Materials Science, University of Szeged, H-6720 Szeged, Aradi vértanúk tere 1, Hungary
The adsorption of ethanol on a CeO2(111) surface and a Co/CeO2(111) model catalyst was studied with near ambient XPS at pressures up to 1 mbar. The main species adsorbed on the surface was found to be ethoxide, formed by dissociative adsorption. Upon ethanol exposure on pristine ceria at 300 K a gradual reduction with increasing pressure was observed; reduction was even further enhanced by heating to 600 K at 0.1 mbar. This effect was attributed to increased diffusion of the Ce3+ centers or lattice oxygen at elevated temperatures. Partial reduction of the ceria layer upon Co deposition was observed. Ethanol strongly reduced the Co particles leaving almost solely metallic Co on the concurrently reduced CeO2 surface at 600 K. While no coke formation occurred during reaction with the pristine CeO2 layer, carbonaceous species were observed at 600 K on the Co/CeO2 model catalyst.