Synthesis of carbon-supported PtRh random alloy nanoparticles using electron beam irradiation reduction method

•PtRh nanoparticles with alloy structure were synthesized using radiochemical process.•Alloying of Pt and Rh were explained by the radiochemical formation process.•PtRh alloy nanoparticles showed high catalytic activities.

Bimetallic nanoparticle catalysts of PtRh supported on carbon were synthesized using an electron beam irradiation reduction method. The PtRh nanoparticle catalysts were composed of particles 2–3 nm in size, which were well dispersed on the surface of the carbon support nanoparticles. Analyses of X-ray diffraction and scanning transmission electron microscopy–energy-dispersive X-ray spectroscopy revealed that the PtRh nanoparticles have a randomly alloyed structure. The lattice constant of the PtRh nanoparticles showed good correlation with Vegard's law. These results are explained by the radiochemical formation process of the PtRh nanoparticles. Catalytic activities of PtRh/C nanoparticles for ethanol oxidation reaction were found to be higher than those obtained with Pt/C.