Effect of chemisorbed methanol on the rate and selectivity of electroreduction processes at a platinized platinum electrode

Abstract

The effect of chemisorbed methanol on the reduction of allyl and crotyl alcohols and alloxan was studied in acid media on a platinized platinum electrode. It has been stated that the composition of reduction products changes significantly as a result of the blocking effect of methanol. In the case of allyl alcohol the rate of saturation of the double bond decreases to such an extent that the main product of the reduction is propene. This phenomenon is explained by the different mechanism of the splitting of C−OH bonds and the saturation of −C=C− bonds. Chemisorbed methanol inhibits the reduction of dialluric acid and thus the only product of the reduction of alloxan at electrodes covered with chemisorbed methanol is dialluric acid in a wide potential range. Explanation is given by the assumption that the formation of dialluric acid from alloxan takes place via ionic mechanism without participation of chemisorbed particles while the reduction of dialluric acid occurs via chemisorbed species.