Master assignment "Exploring the Relationship between Mass Transport and Flow Rate in Aqueous and Organic Electrolytes in Hollow Fiber Electrodes."
Daily supervisors: T. de Koning Gans and A. Berghuis
Background
Humanity is confronted with global challenges such as climate change and the transition into clean energy. Electrochemistry can play a major role in these issues and offer viable solutions to these complex problems. Examples of these solution are hydrogen production, energy storage, producing chemicals and many more. Due to the wide variety of processes, many different kinds of cells, electrolytes and electrode configurations are needed. Therefore, research focuses on developing these kind of technologies.
When developing an electrode, the electrode shape and design has a significant impact on the mass transport. Certain electrode shapes, such as microelectrodes or porous electrodes, are designed to reduce diffusion limitations. These electrodes provide a more accessible surface area for electrochemical reactions. One specific electrode configuration was developed at the UT: a porous electrode, the hollow fiber electrode (HFE) [1]. It can be made from various metals, such as copper [1] and titanium [2]. In Figure 1, SEM images of a titanium HFE can be seen. The electrode is hollow, which allows for gas to be purged through the pores wall. This configuration has three major advantages: scalable production process [2], improved mass transport due to mixing caused by bubble evolution [3] and lastly is the possibility of locally introducing the reactant to the active surface of the electrode.
Figure 1: SEM images of titanium hollow fiber electrode [2].
Assignment
There is evidence that the gas exiting the pores of the electrode create a Nernst diffusion layer [3]. This type of mass transport behavior is found in rotating disk experiments. Here, the mass transport can be manipulated by using different rotation speeds. However, only preliminary experiments have been conducted to study the relationship between flowrate and mass transport [3]. This relationship must be studied systematically in order to get a firm understanding of how the hollow fiber electrode influences the mass transport. This is where this project comes in where you will be investigating the effects of flowrate on mass transport in the hollow fiber electrode configuration. This will be done by applying various aqueous and organic electrochemical systems to hollow fiber electrodes as well as rotating disk electrodes.
Contact
If you are interested in this assignment, or have any questions. Please contact Anneloes Berghuis (a.berghuis@utwente.nl) or Tessa de Koning Gans (t.dekoninggans@utwente.nl)
References
[1] R. Kas et al., “Three-dimensional porous hollow fibre copper electrodes for efficient and high-rate electrochemical carbon dioxide reduction,” Nat. Commun. 2016 71, vol. 7, no. 1, pp. 1–7, Feb. 2016, doi: 10.1038/ncomms10748.
[2] R. P. H. Jong, P. M. Krzywda, N. E. Benes, and G. Mul, “Preparation of Ti, Ti/TiC or Ti/TiN based hollow fibres with extremely low electrical resistivity,” RSC Adv., vol. 10, no. 53, pp. 31901–31908, Aug. 2020, doi: 10.1039/D0RA04905K.
[3] R. P. H. Jong and G. Mul, “Gas flow Stimulated Hydrodynamics for Preparation and Application of Platinized Titanium Hollow Fibre Electrodes,” ChemElectroChem, vol. 9, no. 5, p. e202101135, 2022, doi: 10.1002/celc.202101135.