Flame-based synthesis of core-shell structures using Pd-Ru and Pd cores

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 °C and 150 °C. A Pt ML/Pd(250 °C) has higher Pt mass and specific ORR activities than PtML/Pd(150 °C). This is due to smoother surface of Pd (250 °C) compared to Pd (150 °C). During membrane electrode assembly testing in O2, the Pt mass activity was 0.532 A/mgPt at 0.9 V. The voltage at 1 A/cm2 was 0.613 V, and a peak power density of 0.93 W/cm2 was achieved. © 2014 Elsevier Ltd.