Kinetic studies of molecular oxygen reduction on W 0.013Ru 1.27Se thin films chemically synthesized

Abstract

The reaction of molecular oxygen reduction was investigated on an amorphous W 0.013Ru 1.27Se electrocatalyst compound in a 0.5 M H 2SO 4 solution. The electrocatalyst was synthesized by reacting transition metal carbonyl compounds with the elemental selenium in 1,2-dichlorobenzene (b.p.≈180°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.