Proefschrift
Kinetic and Non-Kinetic Effects for the Alkaline Oxygen Evolution Reaction on NiFeOOH Electrocatalysts
Green hydrogen is produced via a process called water electrolysis. During electrolysis water is split into oxygen and hydrogen.
- Auteur
- O. van der Heijden
- Datum
- 26 juni 2025
- Links
- Thesis in Leiden Repository
Theoretically, this is possible at 1.23 V. However, in reality, a larger voltage is required due to energy losses, with the oxygen producing electrode (anode) accounting for the biggest loss.This thesis focuses on this anode and specifically on the nickel-iron electrode under alkaline conditions. This material is interesting because of its relatively good performance and the use of cheap and abundant materials. However, it is difficult to determine reaction kinetics (such as the Tafel slope) causing conflicting results in the literature.Here, we show that the these kinetic measurements are influenced by experimental parameters, due to different magnitudes of non-kinetic effects. These non-kinetic effects include bubbles, mass transport limitations and uncompensated resistances. We propose an improved method for measuring the Tafel slope. Moreover, we investigated the effect of the electrolyte on the electrode performance and found that mixing sodium or potassium hydroxide with lithium hydroxide improves performance by improving transport within the catalyst layer. So, this thesis contributes to improved kinetic measurements as well as improved understanding of the kinetics of nickel-iron electrodes and its interaction with the electrolyte.