Abstract
UDC 544.653.2
DOI https://doi.org10.5281/zenodo.1053531
The determination of the electrocatalytic activity and selectivity of electrodes with respect to the target process is considered to be of interest both, in the theoretical aspect, for the development of electrocatalysis theory and in application for efficient electrocatalysts, which can be used in electrochemical systems for wastewater treatment. The purpose of the given work was to identify the relationship between the chemical and phase composition of materials based on lead dioxide, their physical-chemical properties and electrocatalytic activity. The major research methods were: quasi-stationary polarization and impedance spectroscopy; photocolorimetry, fluorescent and spectrophotometry in the UV and visible regions, atomic absorption spectroscopy, high performance liquid chromatography (analysis of the solutions). It was shown that the modification of lead dioxide by ionic additives results in significant changes in the electrocatalytic activity of the system in respect to the oxygen evolution reaction and electrochemical oxidation reactions of organic compounds. It was found that at low polarizations the oxygen evolution reaction is limited by the electro-chemical desorption step (the second electron transfer) and its overpotential at PbO2-modified electrodes increases in the order that coincides with the dependence, in which the number of oxygen-containing particles is strongly bounded with the electrode surface. It was found that the rate of organic substances oxidation on the anode materials involved is directly proportional to the amount of oxygen-containing radicals formed on the electrode during the water oxidation.
Keywords: lead dioxide, methanesulfonate electrolyte, oxygen evolution, ozone generation, oxidation of organic compounds.