Core nanoparticles of Pd, Pd-Ru, and Pd supported on an amorphous carbon are deposited, by a flame-based process, onto glassy carbon rotating disk electrodes and gas diffusion layers. A Pt monolayer was deposited using galvanic displacement of an underpotentially deposited Cu monolayer with Pt. The Pt monolayer is then tested to determine the electrochemical surface area and activity toward the oxygen reduction reaction. Depositions of the Pd core were applied at substrate temperatures of 250 degrees C and 150 degrees C. A Pt-ML/Pd(250 degrees C) has higher Pt mass and specific ORR activities than Pt-ML/Pd(150 degrees C). This is due to smoother surface of Pd (250 degrees C) compared to Pd (150 degrees C). During membrane electrode assembly testing in O-2, the Pt mass activity was 0.532 A/mg(pt) at 0.9 V. The voltage at 1 A/cm(2) was 0.613 V, and a peak power density of 0.93 W/cm(2) was achieved. (C) 2014 Elsevier Ltd. All rights reserved.