材料期刊网

Pt/C catalysts were prepared by ethylene glycol (EG) method in weakly acidic solutions adjusted by sodium citrate (Na₃Cit), sodium acetate (NaAc) and sodium hydroxide (NaOH), separately. The e®ects of alkalizing agent, pH and temperature were investigated by transmission electron microscopy (TEM) and CV. The composition and structure of Pt/C catalyst prepared at optimal conditions of 140°C and pH=6.7 adjusted by Na₃Cit was further characterized by X-ray photoelectron microscopy (XPS) and X-ray diffraction (XRD), respectively. The average particle size of Pt/C catalyst prepared using Na₃Cit is 2.1 nm, smaller than that of Pt/C catalyst (2.9 nm) prepared using NaAc, much smaller than that of Pt/C catalyst (100 nm) prepared using NaOH. The electrocatalytic activity of Pt/C catalysts prepared using Na₃Cit and NaAc for ethanol oxidation are 456.6 and 419.2 mA/mgPt, comparative to those of Pt/C catalyst prepared by typical EG method and commercial E- TEK Pt/C catalyst. Finally, the size control mechanism of Pt nanoparticles was discussed.