PtRu Nanoparticle Electrocatalyst with Bulk Alloy Properties Prepared through a Sonochemical Method

Abstract

Properties of PtRu nanoparticles prepared using high-intensity sonochemistry are reported. Syntheses were carried out in tetrahydrofuran (THF) containing Ru3+ and Pt4+ in a fixed mole ratio of either 1:10 or 1:1. X-ray diffraction measurements confirmed sonocation produces an alloy phase and showed that the composition of the nanometer scale metal particles is close to the mole fraction of Ru3+ and Pt4+ in solution with deviations that tend toward Ru enrichment in the alloy phase. The materials gave responses that are similar in terms of peak potential and current density, referenced to the catalyst active surface area, to those of bulk alloys in voltammetry experiments involving CO stripping and CH3OH electrochemical oxidation in 0.1 M H2SO4. The results show that sonochemical methods have the potential to produce nanometer scale bimetallic electrocatalysts that possess alloy properties. The materials have application in mechanistic studies of fuel cell reactions and as platforms for the development of CO tolerant fuel cell catalyst.

One‐Pot Synthesis of Core‐Shell Silver‐Gold Nanoparticle Solutions and Their Interaction with Methylene Blue Dye

“…[14][15][16] The five different bimetallic nanoparticle formulations that can form for gold and silver are shown in Scheme 1. Investigations into bimetallic noble metal alloy combinations such as Pt-Ru, Cu-Pd, Pt-Mo, Pt-W, Pt-Ni and Au-Ag have been made, [17][18][19][20][21] where the Au-Ag combination is the most extensively studied due, in part, to the fact that both the Ag and Au nanoparticles display distinctive optical plasmon absorbances in the visible range. [22][23][24][25] The optical and catalytic properties of the Ag and Au nanoparticles are useful in a diverse range of applications.…”

Applications of Ultrasound to the Synthesis of Nanostructured Materials

“…[32] Casadonte, Korzeniewski and coworkers examined the electrocatalytic activity of sonochemically prepared Pt-Ru bimetallic nanoparticles toward methanol oxidation and revealed that the Pt-Ru nanoparticles display bulk alloy properties. [47] Sonochemical synthesis of metal nanostructures has not been confined to noble metals and their alloys. Xia and coworkers have developed a sonochemical synthetic route for trigonal selenium nanowires.…”

Operando X‐Ray Absorption Spectroscopy of Polymer Electrolyte Fuel Cells

“…The near-edge data of the as-received catalyst are intermediate between the saddle point of the Ru oxide and the metallic catalyst line (red), again confirming a substantially oxidized as-received catalyst. Table 18.1 summarizes the EXAFS structural parameters for a PtRu catalyst prepared sonochemically by Korzeniewski et al in a DMFC operating with 0.1 molar methanol at the anode in comparison to the same catalyst in as-received conditioned [22,23]. In comparison to the XRD-determined Ru mole fraction, the smaller in situ EXAFS-determined Ru mole fractions suggest that the sizes of the nanoparticle crystalline domains under in situ and ex situ conditions are different.…”