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O: Fachverband Oberflächenphysik
O 35: Poster Session I (Metal, semiconductor and oxide substrates: structure and adsorbates; Graphene)
O 35.57: Poster
Dienstag, 12. März 2013, 18:15–21:45, Poster B1
Adsorption of small molecules on ZnO surfaces — •Jakub Goclon and Bernd Meyer — Interdisziplinäres Zentrum für Molekulare Materialien und Computer-Chemie-Centrum, Universität Erlangen-Nürnberg
Despite much experimental effort the co-adsorption of H2 and CO on ZnO surfaces, which is of considerable interest in the context of methanol synthesis from syngas, is not well understood. We performed DFT calculations on CO interaction with clean and partially hydrogenated flat ZnO(1010) as well as stepped (1011) and (2021) surfaces, including both Zn and O terminations. For the thermodynamically most stable configurations we find a very good agreement for the characteristic Zn-H and O-H vibrational frequencies with the experimental IR signatures.
The majority of catalysts are deactivated even by small amounts of
sulfur-containing molecules that are present as impurities in the feed gas.
Under reaction conditions those compounds are hydrogenated to form H2S,
for which ZnO is a very efficient low-temperature adsorbent [1].
In the second part of this work, we examined different surface forms of H2S
on the ZnO(1010) surface and determined the most stable configurations
as function of the H2S chemical potential [2]. In addition, results on
sulfur incorporation into the ZnO surface will be shown.
[1] J.M. Davidson, C.H. Lawrie, K. Sohail, Ind. Eng. Chem. Res.
34, 2981 (1995).
[2] J. Goclon, B. Meyer, submitted to PCCP.