Oxidation of alcohols in acidic and alkaline environments

The electro-oxidation reactions of methanol and ethanol were studied in sulfuric acid and potassium hydroxide solution. Different electrode materials were tested for this reaction including base metal electrodes in the alkaline case. Tests were performed using standard electrochemical techniques such as cyclic voltammetry, chronoamperometry and differential electrochemical mass spectrometry. Comparing both reactions it was found that in the acidic environment the methanol oxidation proceeds faster and is more complete than the ethanol oxidation. However, the situation changes in alkaline solution. Here, the kinetic enhancement of the ethanol oxidation reaction is in many cases so strong that the ethanol oxidation kinetics become faster than the methanol oxidation kinetics at the same metal and under the same conditions.