Iridium–Ruthenium Alloyed Nanoparticles for the Ethanol Oxidation Fuel Cell Reactions

In this study, carbon supported Ir–Ru nanoparticles with average sizes ranging from 2.9 to 3.7 nm were prepared using a polyol method. The combined characterization techniques, that is, scanning transmission electron microscopy equipped with electron energy loss spectroscopy, high resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction, were used to determine an Ir–Ru alloy nanostructure. Both cyclic voltammetry and chronoamperometry (CA) results demonstrate that Ir₇₇Ru₂₃/C bears superior catalytic activities for the ethanol oxidation reaction compared to Ir/C and commercial Pt/C catalysts. In particular, the Ir₇₇Ru₂₃/C catalyst shows more than 21 times higher mass current density than that of Pt/C after 2 h reaction at a potential of 0.2 V vs Ag/AgCl in CA measurement. Density functional theory simulations also demonstrate the superiority of Ir–Ru alloys compared to Ir for the ethanol oxidation reaction