Reconciling Work Functions and Adsorption Enthalpies for Implicit Solvent Models: A Pt (111)/Water Interface Case...

Area of Science:

• Computational chemistry
• Materials science
• Physical chemistry

Background:

• Implicit solvent models efficiently represent solid/liquid interfaces in electrocatalysis, energy storage, and materials science.
• Understanding electronic structure changes at metallic surfaces due to dielectric continua remains a challenge.

Purpose of the Study:

• To compare Poisson-Boltzmann continuum solvation methods with ab initio molecular dynamics (AIMD) simulations for the Pt(111)/water interface.
• To develop a parametrization scheme for implicit solvent models to accurately represent interfacial electronic effects and adsorption energetics.

Main Methods:

• Density Functional Theory (DFT) calculations for the Pt(111)/water interface.
• Comparison of implicit solvent models (Poisson-Boltzmann) with explicit solvent simulations (AIMD).
• Parametrization of implicit solvent cavities based on electric dipole moment changes and geometry-based dielectric cavitation.

Main Results:

• A method is presented to parametrize implicit solvent cavities using the electric dipole moment change at the explicit Pt/water interface to determine the potential of zero charge (PZC).
• Geometry-based dielectric cavitation methods accurately predict aqueous enthalpies of adsorption for phenol on Pt(111).
• The proposed implicit solvent parametrization scheme yields results comparable to explicit solvent simulations for electronic structure changes (density difference profiles, d-band projected density of states).

Conclusions:

• Implicit solvent models, when appropriately parametrized, can accurately capture the energetics of adsorption and key electronic effects of aqueous solvents on metallic surfaces.
• This work provides a computationally efficient scheme for simulating interfacial processes relevant to heterogeneous catalysis and electrochemistry.