Kiss István Z, Munjal Neil, Martin R Scott
Saint Louis University, Department of Chemistry, 3501 Laclede Ave., St. Louis, MO 63103.
Electrochim Acta. 2009 Dec 30;55(2):395-403. doi: 10.1016/j.electacta.2009.02.094.
We investigate the oscillatory electro-oxidation of formic acid on platinum in a microchip-based dual-electrode cell with microfluidic flow control. The main dynamical features of current oscillations on single Pt electrode that had been observed in macro-cells are reproduced in the microfabricated electrochemical cell. In dual-electrode configuration nearly in-phase synchronized current oscillations occur when the reference/counter electrodes are placed far away from the microelectrodes. The synchronization disappears with close reference/counter electrode placements. We show that the cause for synchronization is weak albeit important, bidirectional electrical coupling between the electrodes; therefore the unidirectional mass transfer interactions are negligible. The experimental design enables the investigation of the dynamical behavior in micro-electrode arrays with well-defined control of flow of the electrolyte in a manner where the size and spacing of the electrodes can be easily varied.
我们在具有微流体流动控制的基于微芯片的双电极池中研究甲酸在铂上的振荡电氧化。在宏观电池中观察到的单个铂电极上电流振荡的主要动力学特征在微制造的电化学池中得以重现。在双电极配置中，当参比/对电极放置在远离微电极的位置时，会出现近同相同步电流振荡。当参比/对电极放置得很近时，同步消失。我们表明，同步的原因是电极之间存在微弱但重要的双向电耦合；因此单向传质相互作用可忽略不计。该实验设计能够以易于改变电极尺寸和间距的方式，通过对电解质流动进行明确控制来研究微电极阵列中的动力学行为。
