Density Functional Theory study of electric field effects on CO and OH adsorption and co-adsorption on gold surfaces

A Density Functional Theory (DFT) study of CO and OH adsorption on Au(1 1 1) and Au(1 1 0) surfaces is presented. The analysis includes the effect of an external negative electric field on adsorption characteristics such as binding energies, binding geometries, charge distribution and vibrational frequencies, both on CO and OH individually and in co-adsorbed geometries. The minimal energy pathways for COOH formation from CO and OH co-adsorbed on Au(1 1 1) and Au(1 1 0) were also calculated. The ability of CO to enhance the adsorption of OH on gold is discussed in relation to the surface structure of gold and changes in the work function as induced by the adsorption of CO.