Evaluation of RuxWySez Catalyst as a Cathode Electrode in a Polymer Electrolyte Membrane Fuel Cell

The oxygen reduction reaction (ORR) on RuxWySez is of great importance in the development of a novel cathode electrode in a polymer electrolyte membrane fuel cell (PEMFC) technology. The RuxWySez electrocatalyst was synthesised in an organic solvent for 3 h. The powder was characterised by transmission electron microscopy (TEM), and powder X-ray diffraction (XRD). The electrocatalyst consisted of agglomerates of nanometric size (similar to 50-150 nm) particles. In the electrochemical studies, rotating disc electrode (RDE) and rotating ring-disc electrode (RRDE) techniques were used to determine the oxygen reduction kinetics in 0.5 M H2SO4. The kinetic studies include the determination of Tafel slope (112 mV dec(-1)), exchange current density at 25 degrees C (1.48 x 10(-4) mA cm(-2)) and the apparent activation energy of the oxygen reaction (52.1 +/- 0.4 kJ mol(-1)). Analysis of the data shows a multi-electron charge transfer process to water formation, with 2% H2O2 production. A single PEMFC with the RuxWySez cathode catalysts generated a power density of 180 mW cm(-2). Performance achieved with a loading of 1.4 mg cm-(2) of a 40 wt% RuxWySez and 60 wt% carbon Vulcan (i.e. 0.56 mg cm(-2) of pure RuxWySez). Single PEMFC working was obtained with hydrogen and oxygen at 80 degrees C with 30 psi.