• 中文核心期刊
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基于电化学阻抗谱测试方法研究四氢呋喃水合物的生成和分解过程

Investigation of Formation and Dissociation Processes of Tetrahydrofuran Hydrate Based on Electrochemical Impedance Spectroscopy

  • 摘要: 含水合物沉积物的电学性质极为复杂且影响因素众多, 目前所采用的电阻率参数尚不能充分刻画含水合物沉积物的电学特性。本文提出应用电化学阻抗谱法对四氢呋喃水合物的生成和分解过程进行测试, 采用等效电路模型拟合阻抗谱, 通过分析等效电路元件参数的变化规律研究水合物生成和分解过程的阻抗谱特征。研究发现:① 四氢呋喃水溶液测试体系的电化学阻抗谱可用传荷与扩散共同控制的电极过程的等效电路进行拟合; ② 在降温、水合物生成前和生成后的过程中, 电荷传递电阻和韦伯阻抗能够显著地反映以上三个过程的转换; ③ 升温过程中各电路元件参数总体变化趋势与降温过程相反。研究表明电化学阻抗谱测试法是研究水合物的电学性质及其生成和分解过程动力学机理的一种有效方法, 等效电路元件参数能够从不同的角度揭示水合物生成和分解过程的内在信息。

     

    Abstract: The electrical properties of hydrous sediments are extremely complex and affected by many factors. The widely used resistivity parameter is unable to characterize the electrical properties of hydrous sediments fully. In this paper, the electrochemical impedance spectroscopy method was used to test the formation and dissociation processes of tetrahydrofuran hydrate. An appropriate equivalent circuit model was used to fit the measured impedance spectroscopy. Then the characteristics of the impedance spectroscopy were then discussed based on the analysis of the model parameters. Results are shown as follows.① The impedance spectroscopy of the tested tetrahydrofuran hydrate can be fitted by an equivalent circuit model of the electrode process controlled by charge transfer and diffusion. ② During the processes of temperature decrease and from the beginning to the end of the hydrate formation, the charge transfer resistance and Warburg impedance can mark the transitions of the three processes more significantly. ③ The variation trend of model parameters during the heating process is inverse to the trend during the cooling process. The electrochemical impedance spectroscopy provides an effective way to investigate the kinetic mechanisms of formation and dissociation processes of hydrate, whereas the parameters of the equivalent circuit model disclose the implicit information of the formation and dissociation processes.

     

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