Electrocatalytic Reduction of Oxygen at Au Nanoparticles–Manganese Oxide Nanoparticle Binary Catalysts

Abstract

The electrocatalytic reduction of molecular oxygen has been performed in -saturated solution at binary catalysts of Au nanoparticles and manganese oxide nanoparticles electrodeposited onto glassy carbon (GC) electrodes. Cyclic voltammetric (CV) and rotating ring-disk electrode (RRDE) techniques have been utilized in this study. CV measurements showed that the electrochemically deposited nanoparticles have a good catalytic activity toward the disproportionation of hydrogen peroxide ( in alkaline media) to water and . A significant positive shift of the peak potential of the oxygen reduction reaction (ORR) was observed upon loading Au nanoparticles onto the GC substrate. The combined use of and Au nanoparticles resulted in the occurrence of the ORR at a potential close to that obtained at Pt electrodes, supporting an apparent four-electron reduction pathway as revealed from the RRDE voltammetric results. The current study proposed a novel binary catalyst system (composed of metal/metal oxide nanoparticles) as a very promising candidate to replace the costly Pt-based electrocatalysts in alkaline air electrodes.