Surface Structures of Shape-Controlled Platinum Nanoparticles

Abstract The selectivity and activities of platinum (Pt) particles strongly depend on their sizes and shapes. A technique has been recently reported for controlling the shapes and sizes of Pt particles [1]. Pt particles were prepared by bubbling Ar gas through the solution of K2PtCl4, and the Pt ions were reduced by flowing H2 gas through the solution. The shape control was performed by changing the ratio of the concentration of the capping polymer material to that of the platinum cations used in the reductive synthesis of colloidal particles in solution at room temperature [2]. High percentage of cubic, tetrahedral and octahedral particles have been prepared at room temperature, making it possible for studying the chemical activities of particles with different shapes and facets. This paper aims to study the surface structures of Pt particles prepared by the shape-controlling synthesis technique using high-resolution transmission electron microscopy (HRTEM).