Cathodic reduction of bisulfite and sulfur dioxide in aqueous solutions on copper electrodes: An electrochemical ESR study

I Streeter, AJ Wain, J Davis, RG Compton

    Research output: Contribution to journalArticle

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    Abstract

    The electrochemical reduction of aqueous solutions of sulfite under acidic conditions on copper electrodes is reported, and a mechanism is proposed. Cyclic voltarnmetry at a copper disk suggests the operation of two reduction processes, the dominant process depending on solution pH. At very low pH (0-2), sulfur dioxide is reduced in a two-electron, two-proton reaction, but at higher pH (2-5), bisulfite is the electroactive species, being reduced by a single electron to ultimately yield the SO2.- radical anion. Simultaneous electrochemical electron spin resonance (ESR) measurements using a tubular flow cell support this proposal, and suggest that the radical anion is in equilibrium with dithionite, which is found to decay at low pH. Digisim. modeling of the system is shown to be consistent with this mechimism over the experimental pH range.
    LanguageEnglish
    Pages18500-18506
    JournalJournal of Physical Chemistry B
    Volume109
    Issue number39
    DOIs
    Publication statusPublished - Oct 2005

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    Electrochemical electrodes
    Sulfur Dioxide
    Anions
    Paramagnetic resonance
    Copper
    Dithionite
    Sulfites
    Electrons
    Protons
    Electrodes
    hydrogen sulfite

    Cite this

    @article{fc92f28926f14e2aaa95f7e510ed62f4,
    title = "Cathodic reduction of bisulfite and sulfur dioxide in aqueous solutions on copper electrodes: An electrochemical ESR study",
    abstract = "The electrochemical reduction of aqueous solutions of sulfite under acidic conditions on copper electrodes is reported, and a mechanism is proposed. Cyclic voltarnmetry at a copper disk suggests the operation of two reduction processes, the dominant process depending on solution pH. At very low pH (0-2), sulfur dioxide is reduced in a two-electron, two-proton reaction, but at higher pH (2-5), bisulfite is the electroactive species, being reduced by a single electron to ultimately yield the SO2.- radical anion. Simultaneous electrochemical electron spin resonance (ESR) measurements using a tubular flow cell support this proposal, and suggest that the radical anion is in equilibrium with dithionite, which is found to decay at low pH. Digisim. modeling of the system is shown to be consistent with this mechimism over the experimental pH range.",
    author = "I Streeter and AJ Wain and J Davis and RG Compton",
    year = "2005",
    month = "10",
    doi = "10.1021/jp058119n",
    language = "English",
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    pages = "18500--18506",
    journal = "Journal of Physical Chemistry B",
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    Cathodic reduction of bisulfite and sulfur dioxide in aqueous solutions on copper electrodes: An electrochemical ESR study. / Streeter, I; Wain, AJ; Davis, J; Compton, RG.

    In: Journal of Physical Chemistry B, Vol. 109, No. 39, 10.2005, p. 18500-18506.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Cathodic reduction of bisulfite and sulfur dioxide in aqueous solutions on copper electrodes: An electrochemical ESR study

    AU - Streeter, I

    AU - Wain, AJ

    AU - Davis, J

    AU - Compton, RG

    PY - 2005/10

    Y1 - 2005/10

    N2 - The electrochemical reduction of aqueous solutions of sulfite under acidic conditions on copper electrodes is reported, and a mechanism is proposed. Cyclic voltarnmetry at a copper disk suggests the operation of two reduction processes, the dominant process depending on solution pH. At very low pH (0-2), sulfur dioxide is reduced in a two-electron, two-proton reaction, but at higher pH (2-5), bisulfite is the electroactive species, being reduced by a single electron to ultimately yield the SO2.- radical anion. Simultaneous electrochemical electron spin resonance (ESR) measurements using a tubular flow cell support this proposal, and suggest that the radical anion is in equilibrium with dithionite, which is found to decay at low pH. Digisim. modeling of the system is shown to be consistent with this mechimism over the experimental pH range.

    AB - The electrochemical reduction of aqueous solutions of sulfite under acidic conditions on copper electrodes is reported, and a mechanism is proposed. Cyclic voltarnmetry at a copper disk suggests the operation of two reduction processes, the dominant process depending on solution pH. At very low pH (0-2), sulfur dioxide is reduced in a two-electron, two-proton reaction, but at higher pH (2-5), bisulfite is the electroactive species, being reduced by a single electron to ultimately yield the SO2.- radical anion. Simultaneous electrochemical electron spin resonance (ESR) measurements using a tubular flow cell support this proposal, and suggest that the radical anion is in equilibrium with dithionite, which is found to decay at low pH. Digisim. modeling of the system is shown to be consistent with this mechimism over the experimental pH range.

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    DO - 10.1021/jp058119n

    M3 - Article

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    T2 - Journal of Physical Chemistry B

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