SKM 2023 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 3: Metal Substrates: Adsorption and Reaction of Small Molecules I

O 3.6: Vortrag

Montag, 27. März 2023, 11:45–12:00, CHE 91

Fluctuating nature of CO adlayer structures on metal surfaces — •Sung Sakong and Axel Groß — Ulm University, Ulm, Germany

The dynamics of atomic and molecular adlayers on surfaces is an critical issue in heterogeneous catalysis and electrocatalysis as it determines how reaction partners can meet on the catalyst surfaces. The adlayer formation influences the performance of catalysts and the structure of the electric double layer. Recently, video scanning tunneling microscope (V-STM) experiments have demonstrated the influence of the CO adlayer dynamics on oxygen diffusion on Ru(0001) [1,2] and the dynamical nature of a CO monolayer on Pt(111) [3]. We will present microscopic pictures of CO adlayer fluctuations on Ru(0001) and Pt(111) based on density functional theory (DFT) calculations and kinetic Monte Carlo (kMC) simulations. The calculations demonstrate how local disorder can lower the adsorption energy of a CO adlayer. We will particularly demonstrate the importance of the so-called door opening mechanism for oxygen diffusion on a CO-covered surface [1,2] and the dynamical nature of CO adlayers [3] by comparing DFT-based simulations with V-STM experiments.

[1] A. Henß et al., Science 363, 715 (2019).

[2] S. Sakong et al., J. Phys. Chem. C 124, 15216 (2020).

[3] J. Wei et al., Angew. Chemie. Int. Ed. 59, 6182 (2020).