ELECTROOXIDATION OF ETHYLENE-GLYCOL AND ITS HOMOLOGS ON A NICKEL-OXIDE ELECTRODE

The reaction of electrooxidation of ethylene glycol (EG) on a nickel-o xide electrode in an alkali medium in the region where lower nickel ox ides convert to higher oxides is found to have a fractional order by E G and a second order by hydroxyl ions (at a constant potential by the reference electrode). A mechanism for this process is proposed that in cludes a slow stage where chelate-adsorbed EO molecules interact with the higher nickel-oxides. A corresponding kinetic equation is derived that satisfactorily explains the experimental data. According to NMR s pectroscopy, potentiometric titration, and thin-layer chromatography, oxidation of EG in steady-state conditions yields such products as gly oxal and the formate and carbonate ions. Kinetic parameters are obtain ed for the reactions of electroreduction of 1,3-propanediol, 1,4-butan ediol, glyoxal, and glycolic acid on the nickel-oxide electrode.