A comparative study of the energetics of CO on stepped and kinked Cu surfaces using density functional theory

TL;DR

This study uses density functional theory to analyze how CO adsorption energies vary on different copper surfaces with different atomic arrangements, revealing how surface structure influences adsorption and vibrational properties.

Contribution

It provides a detailed computational comparison of CO adsorption energetics on stepped and kinked Cu surfaces, highlighting the effects of surface coordination and coverage.

Findings

Adsorption energy increases as surface site coordination decreases.

Adsorption energy decreases with increasing coverage, but not uniformly.

Vibrational frequency of metal-C mode increases with decreasing coordination.

Abstract

Our ab initio calculations of CO adsorption on several low and high miller index surfaces of Cu show that the adsorption energy increases as the coordination of the adsorption site decreases from 11 to 6, in qualitative agreement with experimental observations. On each surface the adsorption energy is also found to decrease with increase in coverage, although the decrement is not uniform. Calculated vibrational properties show an increase in the frequency of the metal-C mode with decrease in coordination whereas no such effect is found in the frequency of the CO stretch mode. Examination of the surface electronic structure shows a strong local effect of CO adsorption on the local density of state of the substrate atoms. We also provide some energetics of CO diffusion on Cu(111) and Cu(211).