Anodic Oxidation of Anhydrous Methanol

Abstract

The electrooxidation of anhydrous methanol was studied with several electrochemical techniques. The effect of controlled amounts of water in the nonaqueous system was followed. The product analysis confirmed the production of formaldehyde as the predominant reaction product in this nonaqueous system. The addition of controlled quantities of water brings about changes in the polarization curves presumably owing to the formation of oxides on the platinum surface and to the production of formate ions. Strongly adsorbed species are observed at low anodic polarizations in the completely anhydrous system as well as in the presence of water. The exact nature of these species could not be identified but the formation of a polymeric inert film is suspected. The effect of adsorbed sulfur on the platinum working electrode was also examined; the adsorbed sulfur layer is unstable at high anodic potentials and causes an inhibition of the anodic oxidation of methanol or methoxide ion.