Synthesis of PtCo3 polyhedral nanoparticles and evolution to Pt3Co nanoframes

Abstract

Bimetallic nanoframes have great potential for achieving new levels of catalytic activity in various heterogeneous reactions due to their high surface area dispersion of expensive noble metals on the exterior and interior surfaces of the structure. PtCo3 nanoparticles with polyhedral shapes were synthesized by a hot-injection method. Scanning transmission electron microscopy combined with energy dispersive X-ray spectroscopy (EDS) showed that these nanoparticles demonstrated elemental segregation of platinum to the edges of the polyhedron, forming the basis for a framework nanostructure. The process of preferential oxidative leaching which removed cobalt from the interior of the framework was tracked by EDS and inductively coupled plasma optical emission spectroscopy. This evolution procedure left the platinum-rich edges intact to form a Pt3Co nanoframe. This is the first reported synthesis of a platinum–cobalt nanoframe and could have potential applications in catalytic reactions such as oxygen reduction.