Poisoning of acetone to Pt and Au electrodes for electrooxidation of 2-propanol in alkaline medium

Abstract

Running of direct 2-propanol fuel cell generates liquid acetone as the main product in the anode compartment. Its concentration continuously increases during cell operation. Its effect on the electrooxidation of 2-propanol at the anode catalyst deserves to be addressed. In this study, the influence of acetone concentration and reaction temperature on the electrooxidation of 2-propanol at Pt and Au electrode in alkaline electrolyte is investigated by cyclic voltammetry and chronoamperometry. The results show that the rate of 2-propanol electrooxidation at Pt and Au electrode is remarkably diminished with the increase of acetone concentration. When the concentration of acetone reaches 0.1molL−1, the oxidation current of 2-propanol at Pt and Au electrode decreases by around 50% and 30%, respectively. The effect of acetone can be attributed to its competitive adsorption with 2-propanol on electrodes surface, leading to the poison of electrodes. Increase of reaction temperature decreases the oxidation current of 2-propanol at Au electrode. Au electrode is more tolerant to acetone than Pt electrode at low acetone concentration. Results of this study suggest that new acetone insensitive electrocatalysts are needed for 2-propanol electrooxidation in alkaline electrolytes.