In situ IR study of the electrooxidation of hypophosphite on a polycrystalline nickel electrode

Abstract

Electrooxidation of the hypophosphite ions on polycrystalline nickel in alkaline solutions has been investigated using cyclic voltammetry, chronoamperometry and in situ IR spectroscopy (SNIFTIRS). A spectroelectrochemical flow cell was used in order to keep the composition of the thin layer constant. The spectra were analysed as a function of the electrode potential during the anodic, cathodic scans and at open-circuit potential as a function of time. On the assumption that solvent bands are independent of applied potential, there is some evidence at open circuit for hypophosphite ions adsorbing to the nickel surface through the hydrogen atoms; this orientation persists until oxidation takes place. Phosphite ions were the only oxidation product to be detected.