Near-surface ion distribution and buffer effects during electrochemical reactions
Near-surface ion distribution and buffer effects during electrochemical reactions
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DOI：
10.1039/c1cp21717h
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发表时间：
2011-01-01
影响因子：
3.3
通讯作者：
Mayrhofer, Karl J. J.
中科院分区：
文献类型：
--
作者：
Auinger, Michael;Katsounaros, Ioannis;Mayrhofer, Karl J. J.
本文研究了在旋转铂盘电极上进行氢氧化反应/析氢反应过程中固液界面近表面离子的分布。反应速率，质量传输和所得的表面pH值之间的关系被用来从理论上预测循环伏安法的行为，只使用从文献中获得的热力学和扩散数据，这是由实验测量证实。缓冲液添加对电流信号，表面pH值和离子分布的影响定量描述的分析解决方案和表面pH值的脆弱性，形成或消耗H+在近中性的无缓冲溶液或缓冲介质差的反应过程中突出显示。虽然在这一基础研究中使用的理想条件不能直接应用于真实的场景，但它们确实为更复杂的非均相反应提供了对表面pH概念的基本理解。
The near-surface ion distribution at the solid-liquid interface during the Hydrogen Oxidation Reaction (HOR)/Hydrogen Evolution Reaction (HER) on a rotating platinum disc electrode is demonstrated in this work. The relation between reaction rate, mass transport and the resulting surface pH-value is used to theoretically predict cyclic voltammetry behaviour using only thermodynamic and diffusion data obtained from the literature, which were confirmed by experimental measurements. The effect of buffer addition on the current signal, the surface pH and the ion distribution is quantitatively described by analytical solutions and the fragility of the surface pH during reactions that form or consume H+ in near-neutral unbuffered solutions or poorly buffered media is highlighted. While the ideal conditions utilized in this fundamental study cannot be directly applied to real scenarios, they do provide a basic understanding of the surface pH concept for more complex heterogeneous reactions.