Berlin 2024 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 60: Solid-Liquid Interfaces III: Reactions and Electrochemistry
O 60.4: Vortrag
Mittwoch, 20. März 2024, 15:45–16:00, MA 042
Understanding Competitive Adsorption at Metal-Water Interfaces via Cavity Formation — •Thorben Eggert1,2, Nicolas G. Hörmann1,2, and Karsten Reuter1 — 1Fritz-Haber-Institut der MPG, Berlin — 2Technische Universität München
Adsorption energies from the gas phase differ significantly from their respective values in aqueous environments, e.g. the reduced adsorption energy of phenol on Pt(111) in water [1]. While computationally costly, explicit solvation models can partially capture this reduction, adsorption energies of phenol are not changed in implicit solvation models [2]. The latter deficiency arises from the common approximation to base the cavity formation cost, i.e. the exclusion of solvent by the adsorbate, solely on bulk liquid energetics.
To measure the missing energetic contribution from the competitive binding of adsorbate and solvent, we study the free energy of cavity formation with classical molecular dynamics simulations and free energy perturbation via the Multistate Bennett Acceptance Ratio. We demonstrate that cavity formation at interfaces depends on the interaction strength between the substrate and the solvent, which can be rationalized by the respective adsorption energy [3]. These results allow for a quantification of the competitive nature of adsorption processes at solid-liquid interfaces, which is a prerequisite for a parametrized substrate-specificity in improved solvation models.
[1] N. Singh and C.T. Campbell, ACS Catal. 9, 8116 (2019).
[2] P. Clabaut et al., J. Chem. Theory Comput. 16, 6539 (2020).
[3] T. Eggert et al., J. Chem. Phys. 159, 194702 (2023).
Keywords: Competitive Adsorption; Molecular Dynamics; Cavity Formation; Free Energy Perturbation