Capturing Solvation Effects at a Liquid/Nanoparticle Interface by Ab Initio Molecular Dynamics: Pt₂₀₁ Immersed in Water

Abstract

Abstract. Solvation can substantially modify the adsorption properties of heterogeneous catalysts. Although essential for achieving realistic theoretical models, assessing such solvent effects over nanoparticles is challenging from a computational standpoint due to the complexity of those liquid/metal interfaces. We investigate this effect by ab initio moleculardynamics simulations at 350 K of a large platinum nanoparticle immersed in liquid water. The first solvation layer contains twice as much physisorbed water molecules above the terraces, than chemisorbed ones located only at edges and corners. The solvent stabilizes the binding energy of chemisorbates: 66 % of the total gain comes from interactions with physisorbed molecules and 34 % from the influence of bulk liquid.

Influence of Van der Waals Interactions on the Solvation Energies of Adsorbates at Pt‐Based Electrocatalysts

“…In computational electrocatalysis adsorbate‐solvent and adsorbate‐electrolyte interactions at the interface can be evaluated implicitly (where the solvent is modelled as a continuum with certain dielectric constant), explicitly, or through combinations of the two . Furthermore, efforts have been devoted to determine the minimal number of explicit water molecules needed to stabilize a given adsorbate .…”

Force Field for Water over Pt(111): Development, Assessment, and Comparison

“…6,7 Experimentally and computationally it has been shown that, depending on the catalyst, water can play a non-innocent role during heterogeneous catalysis. [8][9][10][11] However, the computational approaches that are well suited to describe reactions at the solid-gas-phase interface are 2 not necessarily suitable to describe the solid-liquid interface: the amorphous character of these interfaces make static computations questionable, while ab initio molecular dynamics (AIMD) simulations are too costly to be routinely applied [12][13][14][15][16] and also the cost of adaptive QM/MM is prohibitive for metal surfaces. 17,18 Therefore, approximate methods have been developed aiming at representing the solid-liquid interface.…”

Affordable Estimation of Solvation Contributions to the Adsorption Energies of Oxygenates on Metal Nanoparticles

“…Solvent effects may be accounted for using implicit models, 6,[9][10] though it is generally desirable to include them explicitly, especially when strong solvent-adsorbate interactions such as H-bonds are present. 11 Embedded methods exist with explicit solvent molecules in the first solvation shell and an implicit medium beyond, but the results need careful benchmark. [12][13][14] All those models capitalize on the conclusions and advances on the solvation of chemical species, mostly ions, in solution, which is a well-established field of research.…”

“…Hence, one can safely add these solvation energies to In case not only shifts to the energies in vacuum are needed and explicit solvent descriptions are required, micro-solvation is also helpful: for instance, Pt 201 has a diameter of ~1.7 nm and AIMD simulations at 350 K found that ~1/3 of the 122 surface atoms are covered by water. 11 Thus, the high computational cost required to dynamically describe water/metal interfaces at finite temperature makes our static approach useful, as merely three water molecules and no implicit environment are needed.…”