Conductive carbon black supported Pt-Pd nanocomposites were prepared to study a difference of simultaneously and sequentially reduced Pt-Pd nanocomposites using polyol method. The concentration of Pt-Pd alloyed metals on carbon blacks (CB) was adjusted to 20 wt%. The catalysts could be characterized by transmission electron microscopy, X-ray diffraction and thermogravimetric analysis. The electrochemical activities of Pt-Pd were measured by cyclic voltammograms. As a result, electrochemical active surface area (ESA) value of sequentially deposited Pt-Pd/CB was shown to 66 m2/g, which was higher than 55 m2/g of simultaneously deposited Pt-Pd/CB. Besides, average particle size of sequentially deposited Pt-Pd/CB was calculated to 1.7 nm which was smaller than 2.2 nm of simultaneously deposited Pt-Pd/CB.
