Marvin Gornik joined our group as a master student!
12 May 2021
Marvin Gornik from Friedrich-Alexander University Erlangen-Nürnberg is joining our group for his master thesis. He will focus on stability and activity tests of noble metal catalysts for electrooxidation of isopropanol using different polyoxometallates as catalyst mediators. Polyoxometallates have proven to enhance the activity of noble metal catalysts during electrooxidations of alcohols such as methanol or ethanol. However, very less is known about their functioning in isopropanol electrooxidation and their stability. To gain more insights, he will investigate the dissolution of noble metal catalysts modified with polyoxometallates using a scanning flow cell (SFC) coupled with an online inductively coupled plasma mass spectrometer (ICP-MS).
Elisabeth Frömsdorf joined us as a new master student in our OER sub-team!
1 May 2021
Elisabeth Frömsdorf from Friedrich-Alexander University Erlangen-Nürnberg is joining our group for her master thesis. She will focus on the discrepancies between aqueous model systems (AMS) and membrane electrode assemblies (MEA) in proton exchange membrane water electrolyzer (PEMWE) with iridium based catalysts for oxygen evolution reaction (OER). To do so, she will investigate the pH dependence of stability and activity of iridium oxide catalysts using a scanning flow cell (SFC) coupled with an on-line inductively coupled plasma mass spectrometer (ICP-MS).
Gün Deniz Akkoç joined us as a guest researcher!
21 April 2021
Gün Deniz Akkoç, a chemist from İzmir Institute of Technology (Turkey), has joined our group as a guest researcher. His research focuses on high-throughput screening of multi-metal-oxides for (photo)electrochemical performance and stability. Ultimately, the implementation of machine learning techniques is aimed to both efficiently explore and fine-tune the compositional space while creating a material library along the way.
Julius' new paper was published in Nature Communications!
13 April 2021
Our new paper On the limitation in assessing the stability of oxygen evolution catalysts using aqueous model electrochemical cells was published today in Nature Communications. In this work, we tackle the discrepancy in the lifetimes of oxygen evolution reaction (OER) electrocatalysts between aqueous model systems (AMS), which are commonly employed in fundamental research and polymer electrolyte membrane based membrane electrode assemblies (MEA), which are state of the art in today's water electrolyzers.
With a newly developed setup, we present the first measurement of real dissolution rate in an MEA system. A striking difference in the stability of an iridium oxide catalyst in the MEA system was observed compared to our established scanning flow cell coupled to an inductively coupled plasma mass spectrometer (SFC-ICP-MS). Thus, a series of measurements in AMS was performed to search for the origins of this discrepancy.
Our results indicate two main contributors being responsible for the dissolution discrepancy—first, a general overestimation of the acidity of the conditions in the MEA. Second, iridium oxide stabilizes in the MEA system on longer timescales.
We expect our findings to lead to a better understanding of OER catalyst degradation and, subsequently, to better performing water electrolyzers.
More details can be found in Nature Communications under the following link: https://doi.org/10.1038/s41467-021-22296-9.
Nico Röttcher will join us in April 2021 as a new master student!
22 March 2021
Nico Röttcher, master student at the Georg-August University Göttingen, will investigate electrocatalysts for the hydrogen oxidation reaction (HOR) for alkaline exchange membrane fuel cells (AEMFC). Thereby, he will focus on the performance of state-of-the-art electrocatalysts in high-current region using a gas diffusion electrode (GDE) setup. Additional electrochemical methods will be applied to gain mechanistic insights under realistic fuel cell potentials.
Moritz Geuß joined our team as a PhD student!
22 March 2021
Moritz Geuß from the FAU Erlangen-Nürnberg will be working with us in the field of PEM Water Electrolysis, for details see our “Research” page. His research will focus on the degradation of the anodic catalyst layer during high current operation. Combining GDE setup, online ICP-MS and IL-TEM will help to understand degradation mechanisms during long-term operation of PEM Water Electrolyzers. This project will be realized with partners within HI ERN and from the industry.
Dr. Victoria Benavente Llorente will be awarded a Georg Forster Research Fellowship and join us!
17 March 2021
Dr. Benavente Llorente is getting a Georg Forster Research Fellowship for postdoctoral researchers, funded by the Alexander von Humboldt Foundation. And she will join us in September 2021.
Victoria received her Ph.D. in Universidad Nacional de Córdoba, Argentine. During her thesis, she focused on Spectroelectrochemistry and Photoelectrochemistry of nanostructured semiconductors. Her postdoctoral research was related to the hydrogen evolution reaction (HER) on Ni and NiMo composites electrodes. Victoria will investigate the degradation of α-Fe2O3 photoanodes during oxygen evolution reaction (OER) with mass spectrometry (ICP-MS). A deeper understanding of the photoelectrochemical dissolution of α-Fe2O3 is important to design strategies that prevent degradation.
We are looking forward to having you on the team!
Jakob Scholl is joining our group as a master student!
19 January 2021
Jakob Scholl, who studies chemical and biological engineering at Friedrich-Alexander-University, investigates possible high-throughput methods for photoelectrochemical water splitting for his master thesis. The focus lies on developing a high-throughput synthesis route for photoactive anode materials. The materials are characterized by XRD, SEM, and LSM, and additional photoelectrochemical tests are carried out with a scanning flow cell setup.
Valentín Briega Martos joins our group as a PostDoc!
15 January 2021
Dr. Valentín Briega Martos received his Ph.D. from the University of Alicante (Spain) and his previous research was related to the oxygen reduction reaction (ORR) on Pt single crystal electrodes. Valentín will investigate the mechanisms of the electrochemical oxidation, restructuring, and dissolution of Pt from a fundamental point of view by using Pt single crystal electrodes and shape-controlled Pt nanoparticles in mass spectrometry (ICP-MS) and surface X-ray diffraction (SXRD) measurements. This is important for achieving a complete understanding of Pt catalyst degradation on fuel cells.
New paper online: Pt dissolution in realistic fuel cell catalyst layers
15 January 2021
Our new work on Pt dissolution in realistic fuel cell catalyst layers was published in Angewandte Chemie. In this current work we present the first experimental approach to measure Pt dissolution in gas diffusion electrodes (GDE). Therefore we coupled our GDE half-cell setup with inductively coupled plasma mass spectrometry (ICPMS). With this, Pt dissolution in realistic catalyst layers and the transport of dissolved Pt species through Nafion membranes are evaluated directly.
We hereby observe that (i) specific Pt dissolution is increasing significantly with decreasing Pt loading, (ii) in comparison to experiments on aqueous model systems with flow cells, the measured dissolution in GDE experiments is considerably lower and, (iii) by adding a membrane onto the catalyst layer, Pt dissolution is reduced even further. All these phenomena can be attributed to the varying mass transport conditions of dissolved Pt species, influencing re-deposition and equilibrium potential. With the presented method we were also able to measure the diffusion coefficient of Pt species in Nafion, which can be of great importance when modelling fuel cell degradation.
More details can be found in Angewandte Chemie International Edition at the following link: https://doi.org/10.1002/anie.202014711.
Maja Milosevic is also joining our group as a PhD student!
5 November 2020
Maja Milosevic from the University of Belgrade (Serbia) will conduct research in the field of PEM Water Electrolysis, of which the details can be found on our “Research” page. The focus of her research will be on the analysis of anode and cathode catalyst layers during intermittent operation. The main scope is to gain thorough understandings of the catalyst layers degradation in order to optimize the overall cell performance. This project will be realized with partners within HI ERN and outside.
Mária Minichová is joining our group as a PhD student!
2 October 2020
Mária Minichová from the University of Chemistry and Technology Prague (Czech Republic) will focus on high-throughput synthesis of model electrocatalyst libraries for LOHC fuel cells. Mária will investigate the synthesized libraries using physico-chemical characterization tools (laser profilometry, SEM, TEM, XPS, etc.) and carry out electrochemical measurements using scanning electrochemical flow cells.
Pascal Kaiser is joining us as a PhD student!
2 October 2020
Pascal Kaiser, who received his Master of Chemistry from the University of Duisburg-Essen (Germany), will support the interdisciplinary research project to investigate catalyst layers by using our gas diffusion electrode (GDE) setup. The focus of his research will be on advanced catalyst support materials. Thereby, the structure-performance relationship will be investigated to gain deeper insights into mass transport phenomena in catalyst layers for low Pt metal PEMFC.