A Strategy for Fabricating Porous PdNi@Pt Core-shell Nanostructures and Their Enhanced Activity and Durability for the Methanol Electrooxidation

Abstract

Three-dimensionally (3D) porous morphology of nanostructures can effectively improve their electrocatalytic activity and durability for various electrochemical reactions owing to big surface area and interconnected structure. Cyanogel, a jelly-like inorganic polymer, can be used to synthesize various three-dimensionally (3D) porous alloy nanomaterials owing to its double-metal property and particular 3D backbone. Here, 3D porous PdNi@Pt core-shell nanostructures (CSNSs) are facilely synthesized by first preparing the Pd-Ni alloy networks (Pd-Ni ANWs) core via cyanogel-reduction method followed by a galvanic displacement reaction to generate the Pt-rich shell. The as-synthesized PdNi@Pt CSNSs exhibit a much improved catalytic activity and durability for the methanol oxidation reaction (MOR) in the acidic media compared to the commercial used Pt black because of their specific structural characteristics. The facile and mild method described herein is highly attractive for the synthisis of 3D porous core-shell nanostructures.

Highly Porous Carbon Derived from MOF-5 as a Support of ORR Electrocatalysts for Fuel Cells

“…The low content of Ni also confirms that Ni is present as substrate part of the bimetallic Pt-Ni nanoparticles and was not completely detected by XPS which can only probe the sample surface, similar finding have also been reported for Pt-Ni core shell structure. 52 In current studies the X-ray analysis clearly shows the electron interaction of Pt and Ni much like core-shell configuration in the literature but the particles are completely embedded in the carbon matrix-support so, morphological investigation for the exact core-shell structure is not possible (as confirm by TEM analysis To explore the surface area and pore size distribution, N 2 sorption experiments were carried out for PC 950 sample and representative catalysts with maximum Pt loading (15%). The PC 950 exhibits a Type IV isotherm (Figure 3a), which suggests the existence of different pore sizes ranging from micropores to macropores.…”

Effects of Pt shell thickness on self-assembly monolayer Pd@Pt core-shell nanocrystals based hydrogen sensing

“…These shifts in peak positions can be attributed to the induced additional lattice tensile strain on Pd nanocore due to Pt shell or the higher number of Pt atoms and electron donation induced by the Pd [33,34]. However, it is very difficult to describe such electronic effects from the XPS spectra as nanoparticles often exhibit binding energy shifts with respect to the bulk phases due to electronic and final state effects.…”

Core–Shell-Structured Low-Platinum Electrocatalysts for Fuel Cell Applications

“…As for PdM (M = Ni, Co, Fe, and Cu) cores, these have also been extensively studied as catalysts for ORRs and organic small molecules [76,114,115,119,127,128,135,298,400,[493][494][495][496][497][498][499]. In these reports, there are many reported similarities between PdM@Pt with PtM@Pt catalysts.…”

“…By alloying 3d metals into 4d or 5d cores, the lattice parameters of the 4d or 5d core becomes smaller than that of 4d or 5d metals, increasing lattice mismatches with the Pt shell. This in turn strengthens the compressive strain on Pt shells, leading to weakened binding toward adsorbates and improved surface activities on the Pt monolayer [119,121,229,298,502,582,585]. Based on this concept, researchers have also tuned the ratios of the components in cores to optimize catalytic activities [128,586].…”