Stability and Electronic Structures of Pt-Rh Icosahedral Nanoparticles

Abstract

We investigate the energetic stability and electronic structures of Pt-Rh icosahedral nanoparticles based on first-principles calculations. We find that Pt atom energetically prefers vertex and edge sites at the surface rather than subsurface and core sites, which is a tendency similar to PtRh cuboctahedral nanoparticles. This can be attributed to lower surface energy of Pt compared with Rh. Edges of nanoparticles with secondlowest coordination number are the most favorable sites for Pt atom. This could be attributed to the enhanced interatomic distance at the edge site. 1st order moment of d-state electronic contribution for Pt atom exhibits almost negative dependence in terms of Pt coordination number. This can be qualitatively interpreted by positive dependence of 2nd order moment of the density of states for the Pt atom on the coordination number. Pt surface segregation is expected mainly due to contribution from Pt on-site segregation energy compared with weak ordering tendency of Pt-Rh unlike-atom pairs.

Advances in the Rational Design of Rhodium Nanoparticle Catalysts: Control via Manipulation of the Nanoparticle Core and Stabilizer

“…In this review, emphasis is given to the most recent progress related to Rh NP catalysis, with the majority of cited references from 2006 onward. Earlier literature has been comprehensively discussed in a number of excellent reviews. − Moreover, bimetallic − and trimetallic NP alloys containing rhodium and a detailed account of the effects of solid supports on heterogeneous rhodium catalysts are also beyond the scope of this review.…”