Effect of ultrasonic irradiation on carbon-supported Pt–Ru nanoparticles prepared at high metal concentration

Effect of ultrasonic irradiation during the preparation of carbon-supported Pt–Ru nanoparticles was studied to obtain the aqueous dispersion of catalyst at higher concentrations. The nanoparticles formed through the reduction of Pt and Ru ions with sodium borohydride were impregnated on carbon powder (Vulcan XC72R). TEM observation revealed that the sample prepared with ultrasonic irradiation had single-nanometer-sized Pt–Ru particles on the carbon support, while aggregated Pt–Ru particles were observed in the non-irradiated sample. Methanol oxidation current for the catalysts prepared under ultrasonic irradiation was higher than that for the catalysts prepared without irradiation. This promotive effect of ultrasonic irradiation on the catalytic activity was also confirmed at concentrations of Pt, Ru and carbon support as high as 3.0 mM, 1.2 mM, and 1065 mg/l, respectively.