Dynamic Instabilities and Mechanism of the Electrochemical Oxidation of Thiosulfate

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• 作者：Zhanhe Du ; Qingyu Gao ; Jiamin Feng ; Yongchao Lu ; Jichang Wang
• 刊名：Journal of Physical Chemistry B
• 出版年：2006
• 出版时间：December 28, 2006
• 年：2006
• 卷：110
• 期：51
• 页码：26098 - 26104
• 全文大小：179K
• 年卷期：v.110,no.51(December 28, 2006)
• ISSN：1520-5207

文摘

The electrochemical oxidation of thiosulfate is revealed to have two distinct oscillatory regimes in both linearpotential and galvanic voltammograms, where various nonlinear behaviors such as period-2, mixed-modeand quasi-periodic oscillations, and chaos are observed under potentiostatic or galvanostatic conditions.Electrochemical impedance spectroscopy and iR compensation characterization indicate that, depending onthe operating conditions, the system could be either a strictly potentiostatic oscillator or an S-shaped negativedifferential resistance oscillator. Chronoamperometry measurements reveal that the first oscillatory processinvolves a single-electron transfer, whereas within the second oscillatory regime the average number of electronstransferred is around 3.8. Measurements with capillary electrophoresis and chemical methods illustrate thatthe oxidation products include S₂O₆^2-, S₄O₆^2-, S₅O₆^2-, S₃O₆^2-, and SO₄^2-.