Master Graduation Project student Modeling Reaction Mechanisms for Water Splitting

Hydrogen can be generated sustainably by splitting water molecules using sunlight in a photo-electrochemical cell (PEC). However, currently these cells are not yet able to achieve the efficiencies required for commercial use. In a PEC, two half-reactions occur: a reaction that generates hydrogen at the cathode, and a reaction that generates oxygen at the anode. The latter, the oxygen evolution reaction (OER), is commonly regarded as the performance limiting reaction. Technically, the OER occurs through a number of intermediate reaction steps, in which different intermediate chemical species are formed and consumed. Together, these reactions are called the reaction mechanism. The exact mechanism that occurs in the OER remains unclear, and it is likely that a number of competing reaction mechanisms occur simultaneously. In order to investigate the processes and variables that are involved in the OER reaction, we have developed a microkinetic model that is able to simulate the time-evolution of the intermediate species in the photo-electrochemical cell.

With this project we aim to understand which OER reaction mechanism takes place at the interface, by implementing different mechanisms in the existing model framework and comparing them. Optionally, the mechanisms are also compared with experimental data. This could lead us to improving the efficiency of the photo-electrochemical cell as a whole.

Tasks:

• Implement in MATLAB the pre-selected reaction mechanism(s) of the oxygen generating process in photo-electrochemical water-splitting in an existing microkinetic model framework, such that the different mechanisms can be simulated separately as well as simultaneously.
• Simulate the oxygen evolution reaction on a hematite anode at different applied potentials and analyze the reaction mechanism.
• Perform a global sensitivity analysis, using Sobol’s method, of the model including the new reaction mechanism.
• Visualize the reaction mechanism and limiting reactions in an insightful manner.
• Optional: Simulate and analyze the reaction mechanism(s) for different anode material properties (other than hematite).
• Optional: Couple simulation results with experimental data from electro-chemical (FTIR) measurements.

We ask:

• Proficiency in MATLAB: Working with state-space systems, system identification techniques, clean and efficient coding.
• Able to plan and set personal goals and deadlines, managing a long-term project.

This project is a university master graduation thesis project. It will be carried out at DIFFER and is part of two research groups: Electrochemical Materials and Interfaces (Anja Bieberle) and Energy Systems and Control (Matthijs van Berkel). The daily supervisor is Bart van den Boorn.

The intern position will be based at DIFFER (www.differ.nl) and the working location will be at TU Eindhoven. When fulfilling an intern position at DIFFER, you will have an intern status at NWO.

Dutch Institute for Fundamental Energy Research

DIFFER is the Dutch Institute for Fundamental Energy Research; one of the nine research institutes of the Dutch Research Council (NWO). With multidisciplinary energy research, we are committed to making clean energy available to everyone. Our mission in brief: 'Science for Future Energy'.

DIFFER strives to play a central role in fundamental research for the global energy transition. To this end, the institute carries out multidisciplinary and groundbreaking research in the field of nuclear fusion and energy conversion and storage.