A theoretical study of CO adsorption on Cu(211) surface with coverage effects

Area of Science:

• Surface Science
• Computational Chemistry
• Materials Science

Background:

• Understanding carbon monoxide (CO) adsorption on metal surfaces is crucial for catalysis and materials science.
• The Cu(211) surface, featuring both (111) terraces and step-edges, provides a complex model system for studying adsorption phenomena.
• Previous studies have explored CO adsorption on Cu(211), but a comprehensive analysis across various coverages is needed.

Purpose of the Study:

• To investigate carbon monoxide (CO) adsorption on the Cu(211) surface.
• To determine preferred adsorption sites and patterns at different CO coverages.
• To analyze the influence of coordination number and coverage on adsorption energies and properties.

Main Methods:

• Periodic Density Functional Theory (DFT) computations were employed.
• Calculations included energy, geometry, and vibrational data.
• Adsorption was studied at coverages ranging from 0.25 to 1.00 monolayer (ML) on both terrace and step-edge sites.

Main Results:

• At coverages up to 0.50 ML, CO preferentially adsorbs on top or bridge sites at step-edges.
• Above 0.50 ML, alternating adsorption patterns emerge at step-edges, with potential shifts towards terrace sites.
• Step-edge positions exhibited the highest adsorption energies across all studied coverages.

Conclusions:

• CO adsorption on Cu(211) is strongly influenced by the presence of step-edge sites, which are energetically favored.
• Higher CO coverages promote complex, alternating adsorption patterns on both step-edges and terraces.
• Coordination number plays a more significant role than coverage in determining adsorption properties on Cu(211).