Regensburg 2022 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 32: Poster Tuesday: Adsorption and Catalysis 1
O 32.9: Poster
Dienstag, 6. September 2022, 11:00–13:00, P3
First-Principles Study of Methanol and Benzene Adsorption on In2O3(111) — •Andreas Ziegler1, Margareta Wagner2, Ulrike Diebold2, and Bernd Meyer1 — 1Interdisciplinary Center for Molecular Materials and Computer Chemistry Center, FAU Erlangen-Nürnberg, Germany — 2Institute of Applied Physics, TU Wien, Austria
Indium oxide is widely used as transparent conductive oxide for electrodes in semiconductor devices, but it is also a promising new catalyst for hydrogenation and dehydrogenation reactions, e.g. methanol synthesis. To probe the reactivity of the most stable (111) termination of In2O3, we studied the adsorption of methanol and benzene, two prototypical polar and nonpolar molecules, by DFT geometry optimizations and Car-Parrinello molecular dynamics (CPMD) simulations. We find that the unit cell of the In2O3(111) surface is chemically quite heterogeneous: by searching for the most favorable configurations of methanol with increasing coverage from one to nine molecules per unit cell we find that the first three methanol molecules dissociate in one specific region of the unit cell, followed by molecular adsorption on neighboring sites, confirmed by TPD, XPS and ncAFM experiments. Also benzene prefers to adsorb at one specific site in the unit cell. Due to the large size of the unit cell, the benzene molecules are well separated. CPMD simulations show that the molecules can freely rotate and are well trapped at their adsorption site. However, rotation is suppressed for benzene derivatives with additional side groups.