Alkali metal induced effects on coadsorbed carbon monoxide on Co(0 0 0 1): A density functional theory study

The coadsorption of CO on alkali metal (AM = Li, Na and K) precovered-Co(0 0 0 1) are studied b density functional theory. Calculations indicate that the presence of AM atom strongly enhances the stabilization of CO with substrate surface, lowers the surface potential around CO molecule and weakens C–O bond. These findings are compared with the increasing coverage of CO and it is demonstrated that CO adsorption is affected by a short-range AM–CO electrostatic attraction interaction at a short distance (less than 3 Å), particularly an ionic bonding trend between AMδ+ and Oδ− attraction in a p(2 × 2)–(AM + 2CO) overlayer.