Copper Promotion in CO Adsorption and Dissociation on the Fe(100) Surface

Spin-polarized density functional theory computations have been carried out to study the adsorption and dissociation of CO on clean as well as nCu-adsorbed and nCu-substituted Fe(100) surfaces (n = 1-3) at different coverage to explore the Cu promotion effect in CO activation. Increasing Cu content not only lowers CO dissociation energies but also increases CO dissociation barriers as well as making CO dissociation thermodynamically less favorable, and the clean Fe(100) surface is most active in CO adsorption and dissociation. The nCu-substituted Fe(100) surface can suppress CO adsorption and dissociation more strongly than the nCu-adsorbed Fe(100) surface. CO stretching frequencies at different coverages have been computed for assisting experimental investigations.