A MODEL FOR LOW TEMPERATURE ELECTROCHEMICAL PROTON TRANSFER : TEMPERATURE AND ISOTOPE EFFECTS ON KINETIC PARAMETERS
A MODEL FOR LOW TEMPERATURE ELECTROCHEMICAL PROTON TRANSFER : TEMPERATURE AND ISOTOPE EFFECTS ON KINETIC PARAMETERS
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DOI：
10.1063/1.473853
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发表时间：
1997-06
影响因子：
4.4
通讯作者：
A. Kornyshev;A. Kuznetsov;U. Stimming
中科院分区：
文献类型：
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作者：
A. Kornyshev;A. Kuznetsov;U. Stimming
简单的框架，建议在电极上的低温质子转移反应。计算了电极电流和表观传递系数αobs的温度和电位依赖性。其结果与实验观察一致[M. Cappadonia，S. Krause和U.刺激，电化学。Acta，42，841（1997）]，包括外推至T=0 K的αobs接近负值的趋势。αobs的这种行为导致活化能对超电势的弱且相反的依赖性和“熵”因子的强电势依赖性。所观察到的同位素效应基本上是由隧穿氢同位素的质量的变化和介质的同位素相关的特征频率的相应变化来解释的。
Simple framework is suggested for low temperature proton transfer reactions at electrodes. Temperature and potential dependence of the electrode current and apparent transfer coefficient, αobs, are calculated. The results are in accordance with experimental observations [M. Cappadonia, S. Krause, and U. Stimming, Electrochim. Acta, 42, 841 (1997)], including the tendency for αobs extrapolated to T=0 K to approach negative values. This behavior of αobs results in a weak and rather inverse dependence of activation energy on overpotential and a strong potential dependence of the “entropic” factor. The observed isotope effect is basically accounted for by the change of the mass of the tunneling hydrogen isotope and the corresponding changes in the isotope-dependent characteristic frequencies of the medium.