THE ELECTROCATALYTIC REDUCTION OF MOLECULAR-OXYGEN WITH A CO(II)-GLYOXAL BIS(2-HYDROXYANIL) COMPLEX COATED ELECTRODE

The electrocatalytic reduction of molecular oxygen was investigated wi th a Co(II)-glyoxal bis(2-hydroxyanil) complex coated-glassy carbon (G C) electrode in aqueous media. The reduction of O-2 at the modified el ectrode was an irreversible and diffusion-controlled reaction. The com plex coated-CC electrode demonstrated an excellent electrocatalytic ef fect for O-2 reduction in an acetate buffer solution of pH 3.2. The co ated electrode made the O-2 reduction potential shift of 60-510 mV in a positive direction compared to the bare GC electrode depending on pH . The Co(II)-glyoxal bis(2-hydroxyanil) coated electrode converted abo ut 51% of the O-2 to H2O2 via a two-electron reduction pathway, with t he balance converted to H2O.