In situ potential difference fourier transform infrared reflection absorption spectroscopic studies of the electrochemical oxidation of adsorbed carbon monoxide on nickel in alkaline solutions

The spectral properties of CO adsorbed on polycrystalline nickel electrodes in 0.1 M KOH have been examined using in situ potential difference Fourier transform infrared spectroscopy. The results obtained have shown that the voltammetric peak observed in the first linear scan in the positive direction for Ni(poly)/CO(ads) surfaces prepared by a special procedure is associated with the electrochemical oxidation of bridge-bonded CO to generate solution-phase carbonate as the only detectable product. No changes in the stretching frequency of CO (v_CO) could be found as a function of potential in a region negative to the onset of CO oxidation. However, v_CO shifted monotonically toward lower wavenumbers as the coverage of CO was reduced by electrooxidative stripping.