Dynamic Hydrogen Production via Water Electrolysis
Generation of hydrogen by electrochemical water splitting, driven by surplus renewable electricity, is one of the key conversion steps within the future “green” energy transition scenarios. However, water electrolysis (WE) processes able to cope with the fluctuating and intermittent renewable energy sources (RES) are required. Polymer electrolyte membrane (PEM) WE is particularly suitable, because it can readily respond to the demanding dynamics, but currently with high cost due to the expensive materials required to withstand the harsh acidic and oxidative environment. On the other hand, conventional alkaline based WE is a cheaper solution, since abundantly present materials can be utilized, but cannot follow the highly dynamic nature of RES.
In the PSE group and within the Project “DynElectro”, coupling of experimental and modeling approaches is taken over to investigate the dynamics of water electrolysis processes and try to elucidate the underlying reaction, transport and degradation processes at different time and length scales. Our current focus is on the understanding of reaction mechanisms in cooperation with national and international experts in catalysis (Prof. Schlögl, MPI CEC; Prof. Hutchings, U Cardiff)  and the complex mass transport phenomena under two phase flow conditions (Prof. Hanke-Rauschenbach, LU Hannover; Prof. Bouzek, UCT Prague) . Systematic experiments from catalyst to technical electrodes are designed with the help of model-based analysis to obtain a deep mechanistic knowledge on the interplay of reaction mechanisms (Figure DynElectro) and catalyst degradation.
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 Immerz, C., Paidar, M., Papakonstantinou, G., et al.: (2018). Effect of the MEA design on the performance of PEMWE single cells with different sizes. J. Appl. Electrochem., 48, 701-711.