Migration and diffusion coupled with a fast preceding reaction. Voltammetry at a microelectrode.
Migration and diffusion coupled with a fast preceding reaction. Voltammetry at a microelectrode.
复制标题
迁移和扩散与快速的前期反应相结合。
作者：
Aleksander Jaworski;M. Donten;Z. Stojek
本文提出了一种模拟实现的可逆电偶伏安法的数学模型，该模型涉及快速的前向化学反应和混合的扩散和迁移输运。氢电偶H（+）/H（2）满足上述标准。对于强酸，没有前面的反应，而对于弱酸，前面的反应是HA = H（+）+ A（-）。计算的伏安图与实验伏安图进行了比较，在Pt微电极上的强酸和弱酸与过量的和没有支持电解质的还原。计算中的关键假设是氢离子的通量与阴离子无关。这个假设得到了实验事实的支持，即在没有支持电解质的情况下，几种浓度相同的强酸和不同大小的阴离子的波高是相同的。
A mathematical model implemented by simulation is presented for voltammetry of a reversible couple that involves a fast preceding chemical reaction and mixed diffusional and migrational transport. The hydrogen couple, H(+)/H(2), fulfills the above criteria. For strong acids there is no preceding reaction, whereas for weak acids the preceding reaction is HA = H(+) + A(-). The computed voltammograms are compared with experimental voltammograms for the reduction of strong and weak acids at Pt microelectrodes with excess of and without supporting electrolyte. The key assumption in the calculations is that the flux of hydrogen ion is independent of the anion. This assumption is supported by the experimental fact that the wave heights in the absence of supporting electrolyte of several strong acids of equal concentration and with anions of various size are identical.