Development of a Transferable Density-Functional Tight-Binding Model for Organic Molecules at the Water/Platinum...

Area of Science:

• Computational Chemistry
• Materials Science
• Catalysis

Background:

• Modeling metal/water interfaces is crucial for catalytic transformations, especially in biomass conversion.
• Accurate and efficient computational methods are needed to understand reactions at these interfaces.

Purpose of the Study:

• To develop a computationally efficient and transferable method for modeling reactions at platinum/water interfaces.
• To parametrize the density-functional tight-binding (DFTB) method with many-body interactions (DFTB/ChIMES) for platinum systems.

Main Methods:

• Constructed Pt-H, Pt-O, and Pt-C repulsive potential splines.
• Augmented pairwise parameters with many-body interactions using the Chebyshev Interaction Model for Efficient Simulation (ChIMES).
• Compared DFTB and DFTB/ChIMES with DFT reference data for organic molecules on platinum surfaces.

Main Results:

• DFTB/ChIMES significantly improved transferability and accuracy compared to DFTB, reducing RMSD from ~30 kcal/mol to ~10 kcal/mol.
• DFTB/ChIMES accurately captured phenol adsorption on Pt(111), including water solvation effects, unlike DFTB.
• Simulations showed weaker adsorption at solid/liquid interfaces than solid/gas interfaces, aligning with experimental data.

Conclusions:

• DFTB/ChIMES offers a computationally efficient and transferable approach for modeling platinum/water interfaces.
• The method enhances understanding of catalytic reactions, particularly for biomass conversion.
• Further simulations are needed for full convergence, even with the improved DFTB method.