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.