Electrocatalysis of Oxygen Reduction by Cu-containing Polymer Films on Glassy Carbon Electrodes

Abstract

The catalytic activity of poly[(2,2'-bipyridine)copper(II)-μ 4 -oxalato] coated on a glassy carbon electrode (GCE) for O 2 electroreduction is examined using cyclic voltammetry and rotating disk electrode techniques. The cyclic voltammograms show that O 2 is electroreduced on pBpCuOx-coated GCE surfaces at a peak potential of − 0.25 V in pH 4.7 acetate buffer media. The electroreduction of O 2 on pBpCuOx-coated GCE occurs at 450 mV more positive potential than that found at a bare GCE. The catalytic activity originates from Cu(II) coordinated by bipyridine in the complexes and the polymer type Cu-complex films exhibit an enhanced stability compared to monomeric Cu-complexes during the O 2 electroreduction. The rotating disk electrode measurements reveal that the electroreduction of O 2 on pBpCuOx-coated GCE is a four-electron process. Kinetic parameters for O 2 reduction on pBpCuOx-coated GCE are obtained from rotating disk experiments and compared with those on bare glassy carbon electrode surfaces.