Adsorption of acetylene on Sn-doped Ni(111) surfaces: a density functional study

First-principle density functional theory calculations have been performed to investigate the adsorption of C 2 H 2 on Ni(111) and Sn@Ni(111) at different coverages. At low coverage, the C 2 H 2 molecule is strongly adsorbed on Ni(111) and the dissociation of the H atom is not favorable. Furthermore, the more the H atom dissociated, the more unstable the system is. However, the dissociation structure of C 2 H+H has the largest adsorption energy on Sn@Ni(111), indicating that the dissociation structure is more stable than molecular adsorbed C 2 H 2 . At moderate coverage, there is some repulsive interaction between two C 2 H 2 molecules, inducing the decrease in adsorption energy. On Ni(111), the two C 2 H 2 tend to adsorb separately, however, the dimer C 4 H 4 has the largest adsorption energy on Sn@Ni(111). At high coverage, the trimer derivative benzene has the largest adsorption energy on both Ni(111) and Sn@Ni(111) surfaces. The adsorption energies of the formed benzene are very high on the two systems, even larger than those of three individual adsorbed C 2 H 2 .