Adsorbed oxygen-induced cluster reconstruction on core–shell Ni@Pt and Pt clusters

Abstract

Density-functional calculations were performed to study Pt-O bonding interaction on core-shell Ni@Pt and pure Pt clusters composed of 55 atoms each. Based on oxygen adsorption energy and ν(Pt-O) stretching frequency, the global trend of Pt-O bonding strength in the clusters accommodates the successive order of bridge (and/or hcp-like) > fcc-like > vertex site. Further analysis on oxygen-induced reconstruction effect using first nearest neighbor (1NN) analysis shows that 1NN Pt-Pt distribution pattern of surface atoms changes abruptly after oxygen adsorbed. The profiles of distorted 1NN distribution pattern are greatly determined by the position and the number of adsorbed oxygen on the clusters including whether the cluster type is core-shell or not. The broadening distribution pattern clearly indicates deviation of Pt-Pt bond length due to Pt-O bonds formation and the general trend is similar with the one observed in platinum-related spectroscopy studies.

The effects of alloying and segregation for the reactivity and diffusion of oxygen on Cu3Au(111)

“…Results for the segregation and formation of the protective layer suggest that this method could be used to decrease the amount of corrosion and develop high durability materials. The control method of the oxygen reaction proposed by alloying is useful for the design of catalysts for fuel cells, [34][35][36] design of permselective membranes for new energy 37,38 and other such applications.…”

Atomic Oxygen Adsorption on Core-shell Ni@Pt and Pure Pt Nanoparticles

“…. The oxygen adsorption energies for rigid and relaxed clusters are obtained from previous study 13) . Figure 1(a) and 1(b) show the optimized core-shell Ni ＠Pt and pure Pt clusters, respectively, where the surface (shell) atoms arrangement gives 20 identical equilateral triangular faces and all of them share similar (111) facet surface.…”

“…Therefore, the catalyst has greater chance to improve and enhance the current catalytic oxidation of DOC. In previous study 13) , we have investigated the possibility of utilizing core-shell Ni＠Pt nanoparticles as prospective catalyst candidate in DOC. One important result in that study is that the substitution of 1 nm Pt nanoparticles with core-shell Ni＠Pt nanoparticles of similar size could weaken Pt-O bonds.…”

“…There are still some lacks of knowledge about how this cluster reconstruction might aŠect the bonding at Ni/Pt interface, whether it would strengthen or weaken the bonding is still unknown. This concern arises from the fact that oxygen do not only locally induce surface atoms rearrangement on the surrounding adsorption site but also globally aŠect the connecting bonds of all nanoparticle atoms 13) . Similar phenomenon have also been observed in oxidized Na 55 nanoparticle 17) .…”

“…Oxygen adsorption energy on various designated adsorption sites on Ni＠Pt and pure Pt clusters[13]. The unit is given in eV.…”