Ab initio density functional theory was used to investigate the adsorption and diffusion of a single NO molecule on the unreconstructed Pt{100}-(1x1) surface. This appeared to be the first theoretical study of NO diffusion activation energy on the Pt{100} surface. The most stable adsorption position for NO corresponded to the bridge site with the axis of the molecule perpendicular to the surface. The bond of the NO molecule to the surface was through the N-atom. It was found that there was a low adsorption energy when the NO molecule was bonded through the O-atom and the axis was perpendicular to the surface, for the 3 high-symmetry sites. The NO diffusion between bridge-hollow sites, bridge-atop sites and hollow-atop sites was also investigated. The barrier for NO diffusion was 0.41eV, which corresponds to the energy difference between the bridge and hollow sites. This value was around 15% of the highest adsorption energy found on this surface. NO stretch frequencies were also calculated for the 3 high-symmetry sites which were investigated.

NO Adsorption and Diffusion on Unreconstructed Pt{100} Surface. A Density Functional Theory Investigation. V.A.Ranea, E.A.Bea, E.E.Mola, R.Imbihl: Surface Science, 2006, 600[13], 2663-9