Electrooxidation of cyanide ion on a platinized Ti electrode

Decontamination of highly concentrated cyanide solutions by the method of electrochemical oxidation is presented in this work. By using a Ti electrode covered with 600 nm average thickness layer of Pt, the effective electrooxidation of 0.1 M KCN solution is possible when 25 mA cm−2 current density is applied. Current efficiencies of ~60 % are achieved, and almost full removal of the cyanide ions (from 0.1 to 0.00016 M) are reached when 69 kC L−1 of charge is passed. The kinetics of electrochemical reaction of cyanide oxidation was investigated by voltammetry and fast Fourier transform electrochemical impedance spectroscopy (EIS). The kinetic parameters of cyanide ion electrooxidation reaction are determined and the mechanism of anodic reaction is suggested by considering the analysis of EIS data.