Platinum nanoparticles were deposited on reduced graphene oxide (rGO) and nitrogen-doped rGO (rGOÀN) by He/H 2 plasma jet treatment of H 2 PtCl 6 aqueous solution for electroreduction of oxygen. Physical characterization of the prepared catalysts was performed by scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. Electrochemical characterization was carried out by cyclic voltammetry and CO-stripping techniques. The oxygen reduction reaction (ORR) activity of the prepared Pt/rGO and Pt/ rGOÀN catalyst materials was investigated using the rotating disk electrode method in 0.1 M KOH and 0.05 M H 2 SO 4 . In both acidic and alkaline electrolytes, the catalyst materials prepared by the plasma jet method demonstrated superior electrocatalytic properties compared to that of commercial 20 wt% Pt/ C catalyst. Specific activity values for the ORR in acid electrolyte were 2-fold and in alkaline media more than 3-fold higher than that obtained for commercial Pt/C catalyst.