Imaging and characterization of activated CO2 species on Ni(110)

By means of a joint experimental and theoretical approach we provide single molecule imaging and characterization of CO2 on Ni(110), chemisorbed with high charge transfer from the substrate in an activated state that plays a crucial role in the hydrogenation process. Low-temperature scanning tunneling microscopy images of single CO2 molecules are combined with ab initio density-functional-theory calculations, where dispersive forces and zero-point energy estimates have been explicitly accounted for. We obtain a detailed characterization of the adsorption geometries and an estimate of the energies corresponding to the different adsorbed states. A consistent picture of CO2 chemisorption on Ni(110) is provided on the basis of the newly available information, yielding a deeper insight into the previously existing spectroscopic and theoretical data.