LEPS Potential Surface Computation of Adsorption of H₂ on Ni, Cu Metal and Bimetallic Clusters

Chemisorption of H₂ on Ni, Cu, Mn, Ni-Cu and Ni-Mn cluster was computed with an improved LEPS method. The potential curves of the interaction between H and 1CN, 3CN or 4CN adsorption position on these surfaces were calculated with EHMO method. The pseudo-crystal approximation was assumed for bimetallic clusters in the calculation. The parameters D, a dan r₀ in Morse potential function can be obtained by fitting the calculated data with the function. The periodical changes of D, a and r₀ with the adsorption position were expressed with the first five terms in Fourier expansion. The potential surface of H₂ on （111） crystal surface was computed individually with LEPS method. The comparison of various potential surface with each other demonstrated that adsorption of H₂ was localized predominately on 3CN position for Ni and Ni-Mn and 1CN for Cu and Ni-Cu respectively. Addition of Cu into Ni made the adsorption and activation of H₂ on Cu-Ni cluster more effective which was in agreement with the experimental facts in catalytic research.