Electrocatalytic Activity of Methanol Oxidation at a Boron-doped Diamond Electrode in Alkaline Solution

摘要

The electrocatalytic activity of methanol oxidation at a boron-doped diamond (BDD) electrode in alkaline solution is investigated by voltammetry and electrochemical impedance spectroscopy. Methanol oxidation in this work involves the generation of OH radicals. The intermediate, as formaldehyde, adsorbed at the BDD electrode surface is subsequently oxidized to formic acid or CO_2 by OH radicals. Additionally, the reaction is influenced by the ratio of methanol and OH~- concentration in the solution and is enhanced with the increased OH~- concentration. Methanol adsorption at the BDD electrode surface is an important factor and difficult in this work. However, formaldehyde adsorption is more difficult than methanol. Methanol oxidation in this investigation is dominated by organic adsorption at a lower potential range. With the increased potential, it is gradually dominated by the generation of OH radicals.