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O: Fachverband Oberflächenphysik
O 28: Solid-Liquid Interfaces II: Structure and Spectroscopy
O 28.4: Talk
Tuesday, March 19, 2024, 11:15–11:30, H 1012
Exploring Dynamic Solvation Effects at the Electrochemical IrO2/Water Interface — •Nikhil Bapat, Hendrik H. Heenen, and Karsten Reuter — Fritz-Haber-Institut der MPG, Berlin
Upon electrification, solid-liquid interfaces are known to undergo significant alterations, not least due to the potential-induced adsorption of surface species. Computational studies conveniently explore this phenomenon via an ab initio thermodynamics based Pourbaix analysis, which compares the potential-dependent stability of multiple structural and compositional configurations. To render the computational cost tractable, solvation effects are thereby presently if at all mostly only implicitly treated.
Here, we assess this approximation for the highly hydrophilic IrO2(110) oxide catalyst surface by comparing to results from extensive molecular dynamics simulations including explicit water. This approach is computationally enabled at first-principles predictive-quality level by the use of efficient and accurate machine-learning potentials that are trained to density functional-theory data via an active learning approach. The detailed comparison to the analog Pourbaix diagram obtained with implicit solvation sheds light on the effect of dynamic H-bonding networks at the complex, corrugated oxide surface, while the analysis of the potential-dependent interfacial water structure and mobility gives insight to which degree these networks may be mimicked by static ice overlayers.
Keywords: Explicit solvation; Implicit solvation; MLIPs; Oxide surfaces