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O: Fachverband Oberflächenphysik

O 60: Solid-Liquid Interfaces III: Reactions and Electrochemistry

O 60.6: Vortrag

Mittwoch, 20. März 2024, 16:30–16:45, MA 042

Response Properties of Water at the Electrified Pt(111) Surface — •Lang Li, Nicolas G. Hörmann, and Karsten Reuter — Fritz-Haber-Institut der MPG, Berlin

Metal-water interfaces play a fundamental role in electrochemistry. An accurate understanding of their properties is required in any attempt to describe electrochemical phenomena such as electrocatalytic reactions or charge transfer processes. In this work, we benchmark the description of electrified Pt(111)/water interfaces based on ab initio molecular dynamics simulations at applied potential conditions using density functional theory. We apply the potential by introducing excess electrons that are counterbalanced by partially charged hydrogen atoms. This method is tested with a variety of slab setups and cell sizes. We analyze in detail the structure of the interface as well as the obtained capacitance vs. potential curves and compare with published theoretical and experimental results [1,2]. In addition, we decompose the interfacial water response on Pt(111) into dipolar and chemisorption-related contributions as a function of the introduced electronic excess charge, and introduce a nuanced four-state model of interfacial water with one chemisorbed and three physisorbed states. Our results highlight the response of interfacial water to an applied potential and its importance for understanding overall capacitance, in particular at high electrolyte concentrations [3]. [1] A. Bouzid and A. Pasquarello, J. Phys. Chem. Lett. 9, 1880 (2018). [2] J.B. Le, Q.Y. Fan, J.Q. Li, and J. Cheng, Sci.Adv. 6, eabb1219 (2020). [3] L. Li, Y.P. Liu, J.B. Le, and J. Cheng, Cell Rep. Phys. Sci. 3, 100759 (2022).

Keywords: electrochemistry; ab initio molecular dynamics; explicit solvation; Pt(111); water