Modeling stepped Pt/water interfaces at potential of zero charge with ab initio molecular dynamics

Area of Science:

• Surface Science
• Computational Chemistry
• Electrochemistry

Background:

• Stepped metal surfaces exhibit higher activity in electrocatalytic reactions compared to flat surfaces.
• Understanding the structure and electronic properties of metal/water interfaces is essential for designing efficient electrocatalysts.

Purpose of the Study:

• To model stepped platinum/water interfaces at various step densities using ab initio molecular dynamics.
• To investigate the influence of step density on interface structure, water chemisorption, and potential of zero charge (PZC).

Main Methods:

• Ab initio molecular dynamics simulations.
• Modeling of stepped Pt/water interfaces with varying step densities.

Main Results:

• Interface structure and water chemisorption are strongly dependent on step density, with step sites being preferred for chemisorption.
• PZCs of stepped Pt/water interfaces are generally lower than that of Pt(111) and correlate with work function differences.
• Volta potential differences remain consistent across interfaces despite variations in structure and charge transfer.

Conclusions:

• Step density is a critical factor in determining the behavior of Pt/water interfaces.
• The work function offers a predictive tool for estimating PZCs on stepped metal surfaces.
• These findings provide insights into the fundamental properties of stepped surfaces for electrocatalytic applications.