A comparative first-principles study of the adsorption of a carbon atom on copper and nickel surfaces

The adsorption energies of a carbon atom at the most stable adsorption sites on the Cu and Ni(100), (110) and (111) surfaces have been studied by first-principles calculations. The preference order of the adsorption sites for both Cu and Ni surfaces is the same. The (100) hollow site is the most stable one. The diffusion barriers for a C atom on the three surfaces have also been obtained, with the highest mobility on the (111) surface of both metals. Our investigation shows that the adsorption energies of the C atom on Ni are significantly higher in magnitude than those on Cu for all the three surfaces. This phenomenon is mainly due to the interaction and hybridization between C p-orbits and partially filed d-shell of Ni, which forms a stronger binding.