Structure and energetics of liquid water–hydroxyl layers on Pt(111)

Abstract

The interactions between water and hydroxyl species on Pt(111) surfaces have been intensely investigated due to their importance to fuel cell electrocatalysis. Here we present a room temperature molecular dynamics...

Reversible vs Standard Hydrogen Electrode Scale in Interfacial Electrochemistry from a Theoretician’s Atomistic Point of View

“…However, in the case of sulfate adsorption on Pt(111) and Au(111) the combination of frozen water rows together with an implicit solvent was sufficient to yield a qualitative and semiquantitative agreement with experiment. , In general, the liquid nature of water has to be appropriately taken into account in order to faithfully model water/electrode interfaces. Unfortunately, considering the explicit presence of water molecules requires one to perform time-consuming averages, for example, based on ab initio molecular dynamics (AIMD) simulations. − As a computationally attractive alternative, the explicit description of water molecules might be replaced by using implicit solvent models in which the solvent is described by a dielectric continuum just characterized by its dielectric constant. , Unfortunately, benchmark calculations found substantial deviations between AIMD and implicit solvent approaches, as far as the influence of solvation on adsorption energies is concerned. Hence it appears fair to say that further work is required to obtain a reliable and at the same time computationally attractive approach to model interfaces between aqueous electrolytes and electrodes.…”

Reversible vs. standard hydrogen electrode scale in interfacial electrochemistry from a theoretician's atomistic point of view

“…Unfortunately, considering the explicit presence of water molecules requires to perform time-consuming averages, for example based on ab initio molecular dynamics (AIMD) simulations. [48][49][50][51] As an computationally attractive alternative, the explicit description of water molecules might be replaced by using implicit solvent models in which the solvent is described by a dielectric continuum just characterized by its dielectric constant. 35,36 Unfortunately, benchmark calculations found substantial deviations between AIMD and implicit solvent approaches, 52 as far as the influence of solvation on adsorption energies is concerned.…”

Machine Learning Assisted Simulations of Electrochemical Interfaces: Recent Progress and Challenges

“…In addition, Mikkelsen and co-workers also investigated the interactions between liquid water and hydroxyl species on Pt(111) surfaces and analyzed the interfacial structures under different OH coverages (as shown in Figure 2c) using their constructed ensemble of NNPs. 23 According to the planar average density of water molecules away from the Pt(111) surface, they have discovered that at high OH coverages, an around 2 Å depletion zone between the water overlayer and adsorbed water-hydroxyl layer results from the steady elimination of water molecules from the secondary peak in Figure 2c, suggesting that the interface becomes hydrophobic as OH coverage rises. Recently, Hu and co-workers studied the hydrogen evolution reaction at the HCl(aq)/Pt(111) interface through a high-dimensional neural network potential, and thus revealed interfacial coadsorbed H ad /H 2 O ad and the dual mechanistic nature depending on the surface coverage therein.…”

“…It is worth mentioning that during molecular dynamics (MD) simulations, the use of ML can not only guarantee the accuracy of ab initio methods but also maintain the efficiency of classical force fields as a result of achieving a good balance between these two contradictions. Up to now, ML methods have been tried to model metal/water interfaces − and metal oxide/water interfaces − by some research groups, realizing the extension of the size and time scale of simulations. Certainly, as a new field just a few years old, a natural question is what the restrictions of the framework are for modeling electrochemical interfaces, which is worthy of careful attention in the future.…”