Els Tourwé

IRDE And RDE Electrochemical CellsEvaluation: Comparison Of Electron AndMass Transfer

An inverted rotating disk electrode reactor (IRDE) is constructed to facilitate the study of electrochemically formed gas bubbles. The hydrodynamic and mass transfer characteristics of this new cell design are validated by means of an electrochemical reaction with known characteristics, i.e. the ferri/ferro cyanide redox reaction. This validation is done both qualitatively and quantitatively. The qualitative validation consists of comparing the entire polarization curve obtained in the IRDE with the one obtained in the classical RDE set-up under the same experimental conditions. To quantitatively validate the cell another approach was pursued. A previously developed statistically founded method to model an electrochemical system and to quantitatively determine its mass and charge transfer parameters is used. It is found that the mass and charge characteristics in both configurations agree very well.

Modeling and Quantification of Electrochemical Reactions in RDE (Rotating Disk Electrode) and IRDE (Inverted Rotating Disk Electrode) Based Reactors

Whether it is for the design of a new electrochemical reactor or the optimization of an existing electrochemical process, it is of primordial importance to have the possibility to predict the behavior of a system. For example, the process of electrogalvanization of steel on an industrial scale would not be possible without knowing the main and side reactions taking place during the deposition of zinc on the metallic surface. However, understanding their mechanism is only the first point. The characteristic parameters of the reaction need to be identified and quantified in order to obtain a correct reactor design and to achieve the optimal operating conditions. Nowadays, part of the technological know-how still relies on best practice guidance, most often gained from years of experience with trial and error. Condensing those findings into empirical models may help to control some of the process parameters and make predictions of the system behavior within a small operation window. The problem, however, is that such a model acts as a black box and that a profound comprehension of the physical and electrochemical phenomena will fail to come.