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. PtCo 3 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 Pt 3 Co nanoframe. This is the first reported synthesis of a platinum-cobalt nanoframe and could have potential applications in catalytic reactions such as oxygen reduction.

Flexible Honeycombed Nanoporous/Glassy Hybrid for Efficient Electrocatalytic Hydrogen Generation

“…Typically, Figure 3a shows the transmission electron microscopy (TEM) image of the surface that resulted from the dealloying of the Ni 40 Zr 40 Ti 17 Pt 3 MG, where edges with a width of ≈20 nm of the honeycombed structure are clearly observed. [30,34,35] The surface states of the Pt-rich honeycombed surface structure were also investigated by X-ray photoelectron spectroscopy (XPS) (Figure 3c). The TEM-EDS analysis indicates that the atomic ratio of Pt to Ni in the Pt-rich edges is close to 3:1 ( Figure S12, Supporting Information).…”

“…A similar phenomenon was also observed in the formation of nanocrystalline Pt 3 Ni and Pt 3 Co by other corrosion methods. [30,34,35] The surface states of the Pt-rich honeycombed surface structure were also investigated by X-ray photoelectron spectroscopy (XPS) (Figure 3c). The Ni 2p XPS spectrum consists of metallic Ni 0 and two more peaks attributed to Ni 2+ , indicating that the hybrid surface contains metallic Ni as well as unavoidable oxides.…”

Dendritic Core‐Frame and Frame Multimetallic Rhombic Dodecahedra: A Comparison Study of Composition and Structure Effects on Electrocatalysis of Methanol Oxidation

“…These frame nanostructures possess thin skeletons with a thickness less than a few nanometers confined within a larger framework with a size of tens of nanometers. The enhanced catalytic reactivity is due to the thin skeleton structures that increase the quantity of surface atoms available for catalytic reaction, while the confined larger framework retains the stability of the ultrafine structure . Similarly, nanodendrites also exhibit high catalytic activities in various chemical reactions due to ultrafine branches confined within the relatively‐large assemblies .…”

Stability of High‐Performance Pt‐Based Catalysts for Oxygen Reduction Reactions

“…Copyright 2014, Nature Publishing Group. d) Reproduced with permission . Copyright 2016, Nature Publishing Group.…”

“…Yang and co‐workers reported a hot‐injection method to synthesize PtCo 3 nanoparticles with polyhedral shapes. These PtCo 3 NP could be transformed to hollow NFs though liquid‐phase oxidation due to the easy oxidation and dissolution of Co atoms in the inhomogeneous polyhedral structure …”