Kinetics and mechanism of glucose electrooxidation on different electrode-catalysts: Part II. Effect of the nature of the electrode and the electrooxidation mechanism

Abstract

A comparative study has been made of glucose electrooxidation on electrodes made of metals of group VIII, Ag, Au, Cu and glassy carbon as well as of phthalocyanines and porphyrins of cobalt, manganese and iron. It is found that considerable electrooxidation currents are observed for iridium and rhodium (group VIII), and for gold and copper (the copper subgroup). In neutral and alkaline solutions, glucose electrooxidation rates on gold considerably exceed those on platinum. Investigations have been carried out into the main regularities of glucose electrooxidation on a gold electrode in a wide range of potentials, glucose concentrations and pH values. The effect of chloride ions, gluconic acid and amino acids on glucose electrooxidation on gold have been studied. Proceeding from the direct comparison of adsorption data with polarization data obtained under the same conditions, a mechanism of glucose electrooxidation on platinum has been suggested. It is also shown that the mechanism of glucose electrooxidation on gold is similar, in many respects, to that on platinum.