Disproportional Reaction of Copper in Chloride Solution Investigated by Channel Flow Double Electrode

Abstract

A channel flow double electrode was applied to the investigation of a disproportional reaction of Cu in acidic solution containing chloride ions. The disproportional reaction rate could be determined by the collecting electrode, on which the Cu(I) emitted from the working electrode was oxidized to Cu(II). It was found that the disproportional reaction was divided into three regions depending on the chloride concentration: (1) the region without chloride ion or at low concentration of chloride ions, (2) the region in the presence of chloride ions, and (3) the region at high concentration of chloride ions. The disproportional reaction in the regions (2), (3) and is consist of the following anodic and cathodic reactions involving the intermediate CuCl.
Anodic reaction: Cu+Cl^-↔CuCl+e^-
CuCl+Cl^-→CuCl₂^-
Cathodic reaction: Cu²⁺+Cl^-+e^-→CuCl
CuCl+Cl^-=CuCl₂^-