Evaluating Solvent Effects at the Aqueous/Pt(111) Interface.

Area of Science:

• Physical Chemistry
• Surface Science
• Computational Chemistry

Background:

• Liquid-metal interfaces are vital in many surface processes.
• Accurate computational modeling of these interfaces is fundamentally important.
• The influence of solvents, particularly water, on surface chemistry requires systematic investigation.

Purpose of the Study:

• To systematically determine how water presence affects adsorption and catalytic reactions on the Pt(111) surface.
• To investigate the role of chemical descriptors in predicting solvation effects.
• To develop predictive models for solvation impacts on surface processes.

Main Methods:

• Density functional theory (DFT) with implicit solvation models.
• Modeling adsorption of 41 adsorbates and four catalytic reactions.
• Analysis of chemical descriptors (dipole moment, adsorbate charge) and development of artificial neural network (ANN) models.

Main Results:

• Adsorption energies changed by up to 0.44 eV in water; reaction energies changed by up to 0.23 eV.
• Solvation effects correlate with simple descriptors like dipole moment and adsorbate charge.
• ANN models incorporating descriptors showed predictive capabilities.
• Hydrogen bonding effects were noted but largely absent in implicit models.
• Solvents with low dielectric constants exhibited minor solvation effects.

Conclusions:

• Water significantly influences adsorption and reaction energetics on metal surfaces.
• Simple chemical descriptors and ANN models can predict and explain solvation effects.
• Implicit solvation models may not capture all relevant solvent interactions, such as hydrogen bonding.
• Guidelines are provided for assessing the importance of solvation in surface chemistry modeling.