Density functional theory calculation of platinum surface segregation energy in Pt 3Ni (111) surface doped with a third transition metal

Abstract

We have used density functional theory method to calculate the Pt surface segregation energy in the Pt 3Ni (111) surface doped with a third transition metal M and thus investigated the influence of component M on the extent of Pt segregation to the outermost layer of these Pt 3Ni/M (111) surface. As a third component in the Pt 3Ni/M (111) surface, V, Fe, Co, Mo, Tc, Ru, W, Re, Os, and Ir were predicted to lead to even more negative Pt surface segregation energies than that in the based Pt 3Ni (111) surface; Ti, Cr, Mn, Cu, Zr, Nb, Rh, Hf, and Ta would still retain the preference of Pt segregation to the surface but with less extent than the replaced Ni, while Pd, Ag, and Au would completely suppress the Pt segregation to the Pt 3Ni/M (111) surfaces. Furthermore, we examined the relation between the Pt surface segregation energy in the Pt 3Ni/M (111) surfaces and the material properties (lattice parameter, heat of solution, and Pt surface segregation energy) of binary alloys Pt 3M. It was found that the surface energy effect, strain effect, and heat of solution effect induced by the doped element M would collectively affect the Pt surface segregation energy in the Pt 3Ni/M (111) surfaces.