Kinetic regularities of electrochemical oxidation of the methionine anion on platinated platinum
The purpose of this study was the determination of the kinetic regularities of the methionine electrooxidation process on the Pt(Pt) electrode in an aqueous-alkaline medium. The main kinetic regularities of the methionine anion electrooxidation process were determined using by the methods of cyclic voltammetry, coulometry, and electrochemical impedance spectroscopy. The concentration of methionine in the alkaline solution before and after anodic oxidation was determined spectrophotometrically using spectrophotometer UNICO 2800. The measurements were carried out at room temperature both in an argon atmosphere and in an aerated aqueous solution. The results of voltammetric measurements were adjusted for the limiting oxygen recovery current and the charging current of the double electric layer. The range of potentials of the electrochemical activity of the methionine anion on the Pt(Pt) electrode, the number of electrons involved in the anode process, and its kinetic scheme were determined. The main product of the electrooxidation of methionine in an alkaline medium on Pt(Pt) was the methionine sulfoxide anion. It was shown that the electrooxidation of the methionine anion on Pt (Pt) was carried out from the adsorbed state and was irreversible.