Modeling adsorption of CO2 on Ni(110) surface

The adsorption of CO2 on Ni(110) surface is simulated within the framework of density functional theory using ab-initio pseudopotentials. Beyond possible adsorbed geometries with C2v symmetry, suggested by analogy with the formate adsorption, a geometry with lower symmetry but higher adsorption energy is found and analyzed. Common features of the adsorbed geometries are non-negligible electronic charge transfers from the metal to the molecule ranging from 0.5 to 0.9 electrons in different cases and bending of the molecule with C atom closest to the surface. In the clean surface case we found an enhancement of the magnetic moments of surface and subsurface Ni atoms with respect to bulk, which is partially attenuated by CO2 chemisorption. Both local spin density (LSDA) and generalized gradient correction (GGA) approximations are used for the exchange-correlation functionals: at variance with GGA, LSDA functional is not reliable for energetics, although the results concerning geometric and some electronic properties are almost similar with the two functionals