New Publication in Nature Communications
The research results of the scientists around doctoral researcher Julius Knöppel and team leader Dr. Serhiy Cherevko could lead to more stable water splitting devices.
HI ERN researchers have made an important contribution to the subject of catalyst development. Their new paper On the limitation in assessing the stability of oxygen evolution catalysts using aqueous model electrochemical cells was published in Nature Communications. In this work, the scientists tackle the discrepancy in the lifetimes of oxygen evolution reaction (OER) electrocatalysts between aqueous model systems (AMS), 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.
The work was a collaborative effort of the Helmholtz Institute Erlangen-Nürnberg for Renewable Energy (HI ERN) at Forschungszentrum Jülich and the Center for Applied Energy Research Garching (ZAE Garching) within the Kopernikus P2X Project funded by the German Federal Ministry for Education and Research (BMBF).
The team used a newly developed setup to 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 an established aqueous model system, the 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.
The 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. This could 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:
The interview with Julius Knöppel: “Water electrolysis plays a crucial role in the transition to a sustainable energy system”