Evaluation of Ru x W y Se z Catalyst as a Cathode Electrode in a Polymer Electrolyte Membrane Fuel Cell

The oxygen reduction reaction (ORR) on Ru x W y Se z is of great importance in the development of a novel cathode electrode in a polymer electrolyte membrane fuel cell (PEMFC) technology. The Ru x W y Se z 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 (∼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 H 2 SO 4 . The kinetic studies include the determination of Tafel slope (112 mV dec –1 ), exchange current density at 25 °C (1.48 × 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% H 2 O 2 production. A single PEMFC with the Ru x W y Se z 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% Ru x W y Se z and 60 wt% carbon Vulcan (i.e. 0.56 mg cm –2 of pure Ru x W y Se z ). Single PEMFC working was obtained with hydrogen and oxygen at 80 °C with 30 psi.