Limiting currents in the anodic oxidation of methanol on platinum

Abstract

The limiting currents observed by Pavela for the anodic oxidation of methanol on platinized platinum electrodes have been further interpreted. In alkaline electrolytes the limiting currents depend on the concentrations of methanol and sodium hydroxide and are caused by slow diffusion of either methanol or sodium hydroxide. In sulphuric acid electrolyte the limiting currents depend on methanol concentration in a manner which can be ascribed to slow diffusion of methanol at low methanol concentrations. At high methanol concentrations in sulphuric acid the mechanism becomes complex, and self-poisoning coupled with slow adsorption appears to cause the unexpectedly low limiting currents.