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

By means of a joint experimental and theoretical approach we provide the first 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 temper- ature 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 pic- ture 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.