Structure and stability of platinum nanocrystals: from low-index to high-index facets

Abstract

High index surfaces are introduced into Pt nanocrystals because they are expected to exhibit higher catalytic activity than low index planes such as {111}, {100}, and even {110}. This article presents a systematic investigation on the structure and stability of polyhedral Pt nanocrystals with both low-index and high-index facets by means of atomistic simulations. It has been found that the stability of Pt nanocrystals depends strongly on the particle shape and surface structures. Those nanocrystals, enclosed by high-index facets of {310}, {311}, and {331}, possess better stability and higher dangling bond density of surface compared with those ones with low-index facets, such as {100} and {110}, suggesting that they should become preferential candidates for nanocatalysts. The octahedral nanocrystals with {111} facets, though they have excellent structural and thermal stabilities, present the lowest dangling bond density of surface.