Study of Kinetics of Copper Oxidation by Electrolysis Under Non-Stationary Conditions

Abstract

Data on the study of the kinetics and mechanism of copper electro-oxidation -reduction processes in alkaline and neutral solutions were obtained in this work. Patterns of the electrochemical oxidation of copper using alternating current were established. Based on the data of polarisation measurements kinetic parameters were calculated: the heterogeneous rate constant, the effective activation energy of copper electro-oxidation, which allow to establish the course of the metal oxidation process in alkaline and neutral environments and its characteristics. Potentiodynamic measurements in alkaline solutions at a copper anode indicate the formation of Cu2O, CuO и Cu(OH)2. Anodic dissolution of copper in neutral salt solutions includes two main stages: the formation of Cu(I) and Cu(II) ions. It was found that the product of oxidation at high potentials is the Cu(II) ion. The nature of the anion electrolyte affects the rate of copper anodic oxidation, while the process occurs more efficiently in solutions of sulfate and sodium chloride and is accompanied by significant polarisation. Based on the study of kinetics the possibility of obtaining powders of metal oxide was shown, which further allowed to determine the parameters of the electrolysis process in non-stationary conditions in order to obtain highly dispersed materials based on copper oxides with specific physico-chemical properties.