Kinetic studies of molecular oxygen reduction on W0.013Ru1.27Se thin films chemically synthesized

The reaction of molecular oxygen reduction was investigated on an amorphous W0.013Ru1.27Se electrocatalyst compound in a 0.5 M H2SO4 solution. The electrocatalyst was synthesized by reacting transition metal carbonyl compounds with the elemental selenium in 1,2-dichlorobenzene (b.p. approximate to 180 degrees C), under refluxing conditions for 20 Hs. The sample was characterized by Neutron Activation Analysis (NAA) and Scanning Electron Microscopy (SEM). The characterization of the electrocatalyst indicated that the material, in a thin film form, consisted of an amorphous phase with a distribution of nano-sized particles. Electrochemical studies were carried out by a using a Rotating Disc Electrode (RDE) and a Rotating Ring-Disc Electrode (RRDE) techniques. The RDE and RRDE measurements indicated that the electrocatalyst is active for molecular oxygen reduction in acid media with multi-electron charge transfer (n = 4e(-)), to form water. The reaction order and the heterogeneous rate constants for a simple mechanism were evaluated. (C) 1997 Elsevier Science S.A.