Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland.
Department of Physical Chemistry, Eötvös Loránd University of Budapest, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary.
Anal Chem. 2020 Mar 17;92(6):4301-4308. doi: 10.1021/acs.analchem.9b04999. Epub 2020 Mar 4.
The use of rotating disk electrodes (RDEs) is probably the most convenient way of studying simple electrode reactions under well-defined transport conditions. Standard RDEs become, however, less expedient when the studied electrode process is a complex one, leading to the formation of various reaction products. In these cases, the accurate detection and quantification of the formed products are desirable. If the formed products are gaseous, then the usual way of quantifying them is the use of online gas chromatography (GC), a method that is not compatible with open RDE cells. In order to overcome these difficulties, we present here a sophisticated inverted RDE (iRDE) cell design. The design combines various advantages: it is amenable to the same mathematical treatment as standard (downward-facing) RDEs; it can be operated airtight and coupled to online GC; and due to its upward-facing design, the electrode surface is less prone to blockage by any formed gas bubbles. The iRDE&GC design is tested using simple model reactions and is demonstratively used for studying the electrochemical reduction of CO, accompanied by parasitic hydrogen evolution, on a silver electrode.
旋转圆盘电极 (RDE) 的使用可能是在明确的传输条件下研究简单电极反应最方便的方法。然而，当研究的电极过程比较复杂，导致形成各种反应产物时，标准 RDE 就不那么方便了。在这些情况下，期望能够准确检测和定量形成的产物。如果形成的产物是气态的，那么通常的定量方法是使用在线气相色谱 (GC)，但这种方法与开放式 RDE 池不兼容。为了克服这些困难，我们在这里提出了一种复杂的倒置 RDE (iRDE) 池设计。该设计结合了各种优点：它可以与标准（向下）RDE 进行相同的数学处理；它可以密封操作并与在线 GC 耦合；并且由于其向上的设计，电极表面不易被任何形成的气泡堵塞。使用简单的模型反应对 iRDE&GC 设计进行了测试，并成功用于研究银电极上 CO 的电化学还原，同时伴随着寄生的析氢反应。
