EXPERIMENTAL-EVIDENCE DEMONSTRATING THE OCCURRENCE OF REDUCTION PROCESSES OF CLO4- IONS IN AN ACID-MEDIUM AT PLATINIZED PLATINUM-ELECTRODES

It has been shown that an unexpected cathodic current appears during some cyclic voltammetric, voltradiometric and transient measurements at platinized electrodes carried out in the presence of HClO4 supporting electrolytes. The distortion of voltammetric behaviour depends strongly upon the concentration of HClO4 and the sweep rate. The observed phenomena can be almost completely eliminated by addition of HSO4- or Cl- ions to the solution phase. Radiotracer adsorption studies show that the adsorption of these anions plays a dominant role in the inhibition process. The phenomena observed are explained by the assumption that the reduction of adsorbed ClO4- ions takes place in a wide potential range under certain experimental conditions.