A simple process for the synthesis of carbon supported Pt and Pt/Ru electrocatalysts was investigated. Borrowing from the homogeneous catalyst preparation, this process uses a surfactant as a stabilizer which prevents the metal colloids from aggregation during the reduction process without influencing the deposition of the colloids onto the carbon support. Chemical, morphological and crystallographic properties of the newly prepared electrocatalysts were characterized using various surface techniques including X-ray diffraction (XRD), Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). These techniques show that mono-size, well-dispersed metal colloids can be formed and successfully supported on the carbon black. Moreover, the size of metallic colloids prepared by this method can be manipulated by controlling the synthesis temperature and is independent of the catalyst loading. Electrochemical characterizations show that in comparison with commercial E-TEK electrocatalysts, surfactant-based Pt/C electrocatalysts possess similar catalytic activity in terms of oxygen reduction and higher CO tolerance performance can be obtained by the surfactant stabilized Pt,Ru/C.