Based on the unique catalytic properties of Pt by using its single layer on well-defined inexpensive nanosubstrates one can maximize its activity at the oxygen fuel cell cathode. This illustrates an efficient way of using Pt while overcoming its limited supply. We present a highly active and stable ORR catalyst, consisting of PdNi core-shell nanoparticles, which was protected against decomposition in acid by Au atoms and activated for oxygen reduction with a Pt monolayer. The roles of each component in the catalyst is investigated and in the best case the catalyst showed a Pt group metal mass activity that was approximately 3 times higher than that of the commercial Pt/C electrocatalyst. The Au protected PdNi core-shell nanoparticles were found to be stable support for Pt under high oxidizing conditions. (C) 2013 Elsevier Ltd. All rights reserved.