Dissociative dynamics of O2 on Ag(110)

Area of Science:

• Surface Science
• Chemical Physics
• Computational Chemistry

Background:

• The reactivity of metal surfaces is crucial for catalysis and material science.
• Understanding molecule-surface interactions, like oxygen on silver, informs reaction mechanisms.

Purpose of the Study:

• To investigate the dissociative dynamics of O2 molecules on the Ag(110) surface.
• To determine the energy barriers and reaction pathways for O2 dissociation on Ag(110).

Main Methods:

• Classical and quasiclassical trajectory calculations were performed.
• An adiabatic six-dimensional potential energy surface (PES) was constructed using spin-polarized density functional theory.

Main Results:

• The minimum energy barrier for O2 dissociation on Ag(110) is 0.36 eV, significantly lower than on Ag(100) and Ag(111).
• Significant dissociation requires initial energies of 0.9 eV (classical) or 0.6 eV (quasiclassical) under normal incidence.
• Off-normal incidence shows dissociation primarily near the long-bridge site with higher barriers.

Conclusions:

• The Ag(110) surface exhibits higher intrinsic reactivity towards O2 dissociation due to lower energy barriers.
• A reduced configurational space for dissociation limits reactivity at lower incident energies.
• Computational findings explain experimental observations of limited direct dissociation at low energies.