Abstract: CO and O adsorption and co-adsorption on Rh(111) surfaces were studied by density functional theory calculations. Three types of co-adsorption systems, (2×2)-(CO+O), (2×2)-(2CO+O), and (2×2)-(CO+2O), were considered from energy, geometry, work function, and chemical shift points of view. The interactions between CO and O are repulsive, which is explained in terms of bonding competition. The calculated chemical shift of CO and O agrees well with experimental studies, which convince that it is a powerful method to predict the adsorption from theoretical chemical shifts.

Key words: density functional theory, carbon monoxide, oxygen, adsorption, chemical shift