Computational Insights into Reorientation-Mediated Water Diffusion on Pt(111): Comparison to H₂O/Pd(111)

Area of Science:

• Surface Science
• Computational Chemistry
• Materials Science

Background:

• Understanding water diffusion on metal surfaces is vital for catalysis, corrosion, and electrochemistry.
• Water's interaction with metal surfaces influences key electronic and chemical processes.

Purpose of the Study:

• To investigate the role of water reorientation in surface diffusion on different metal surfaces.
• To elucidate the impact of water-metal interactions on electronic properties like orbital competition and electron transfer.

Main Methods:

• Density Functional Theory (DFT) calculations were employed to model water diffusion.
• Analysis focused on orbital competition, HOMO couplings, electron transfer, and vibronic couplings.

Main Results:

• Palladium (Pd) and Platinum (Pt) surfaces exhibit distinct modulation of water reorientational diffusion.
• Water diffusion on Pt(111) breaks the orientation-dependent orbital competition seen on Pd(111).
• Differences in HOMO couplings, electron transfer patterns, and vibronic couplings were observed between H2O/Pd(111) and H2O/Pt(111) systems.

Conclusions:

• Water reorientation is a critical factor in transient surface diffusion and electronic catalytic mechanisms.
• The study reveals fundamental differences in water-metal bonding and interactions on Pd(111) versus Pt(111).
• Findings provide insights into designing efficient catalysts involving water on metal surfaces.