Theoretical Investigation Of Coverage Effects Of CO Adsorption On Cu(100) Surface

Abstract

This work investigates the CO adsorption on the metallic Cu(100) surface using periodic DFT computations. CO adsorption was studied at varying coverages from 1/16 ML to 1/1 ML for a combination of adsorption positions (4-fold, bridge and top). The results showed that adsorption energies are coverage dependent, however, not enough to identify the adsorption site and coverage. However, C-O stretching frequencies are almost unique for studied coverage and adsorption positions. CO adsorption energy changes between -250 kJ/mol to +21 kJ/mol; similarly, the vibrations’ range in the 1702 cm-1 to 2110 cm-1 interval, within the studied coverage and adsorption positions. Nevertheless, under the saturation coverage (θCO ≈ 0.55ML) the preferable adsorption site is the on-top position identified with a C-O stretching frequency around ~2100 cm-1 and with ~117 kJ/mol adsorption energy.