Quijada, C. and Huerta, F.J. and Morallon, E. and Vazquez, J.L. and Berlouis, L.E.A. (2000) Electrochemical behaviour of aqueous SO2 at polycrystalline gold electrodes in acidic media: a voltammetric and in situ vibrational study: Part 1. Reduction of SO2: deposition of monomeric and polymeric sulphur. Electrochimica Acta, 45 (11). pp. 1847-1862. ISSN 0013-4686Full text not available in this repository. (Request a copy from the Strathclyde author)
The electro-reduction of SO2 has been monitored by using cyclic voltammetry, FT-IR spectroscopy and SER spectroscopy. Prior to the bulk reduction, SO2 is reduced to yield a monomeric sulphur adlayer at a maximum coverage of about 0.25. The sulphur adlayer undergoes a reversible redox surface process at E<0.0 V (RHE), which implies a change in the frequency of the Au---S stretching mode from 270 to 300/310 cm−1. In the potential region encompassing the bulk reduction voltammetric peak, infrared spectra display a band at 2585 cm−1 attributable to a S---H vibration from a soluble species. Accordingly, H2S or H2Sx were proposed as tentative bulk reduction products. In positive sweeps a broad anodic wave develops between 0.2 and 0.6 V that leaves polymeric sulphur species adsorbed at multilayer level, with a S---S stretching mode at 460 cm−1 and a S---S---S bending vibration at 218 cm−1. Multilayer sulphur can be removed reductively under a sharp cathodic peak. According to literature of the S(-II)/Au system, removal proceeds to yield soluble S(-II) species, via intermediate polysulphides.
|Keywords:||sulphur dioxide, sulphur adsorption, gold electrode, cyclic voltammetry, SER spectroscopy, FT-IR spectroscopy, electro-reduction, Chemistry, Chemical Engineering(all), Electrochemistry|
|Subjects:||Science > Chemistry|
|Department:||Faculty of Science > Pure and Applied Chemistry|
|Depositing user:||Strathprints Administrator|
|Date Deposited:||01 Jul 2010 15:52|
|Last modified:||04 May 2016 16:40|