Within a joint collaboration between the ESRF – The European Synchrotron, Johnson Matthey and the Technische Universität Berlin, our PhD student Michal Ronovský is working on the hydrogen fuel cells and water electrolyzers project.

The future of Europe’s energy security and the world’s climate stability depends on our ability to make a transition from fossil fuels to energy systems based on renewable sources. In this respect, an energy storage infrastructure based on hydrogen as an energy carrier is being considered. Even though the development of the two main components of such a system, fuel cells and electrolysers, is well advanced, the widespread adoption is hindered by the high cost. A significant cost contribution comes from the use of scarce platinum group metals (PGMs), Pt in fuel cells and Pt and Ir in electrolyzers.

Therefore, much of the research and development is directed toward lowering the precious metal content and increasing the durability of the nano-catalysts typically used for these applications. In this project, we propose to systematically investigate the stability of a new generation of catalyst materials, which are now being evaluated for commercial use, by means of in-operando studies using high-energy X-ray scattering and X-ray spectroscopy. The aim is to compare the stability trends in the actual PEMFC and PEMWE devices for different combinations of catalyst nanoparticles (NPs) and supports, in order to develop more stable and lower PGM-loading composite materials.

𝐀𝐬𝐬𝐞𝐬𝐬𝐢𝐧𝐠 𝐔𝐭𝐢𝐥𝐢𝐳𝐚𝐭𝐢𝐨𝐧 𝐁𝐨𝐮𝐧𝐝𝐚𝐫𝐢𝐞𝐬 𝐟𝐨𝐫 𝐏𝐭-𝐁𝐚𝐬𝐞𝐝 𝐂𝐚𝐭𝐚𝐥𝐲𝐬𝐭𝐬 𝐢𝐧 𝐚𝐧 𝐎𝐩𝐞𝐫𝐚𝐭𝐢𝐧𝐠 𝐏𝐫𝐨𝐭𝐨𝐧-𝐄𝐱𝐜𝐡𝐚𝐧𝐠𝐞 𝐌𝐞𝐦𝐛𝐫𝐚𝐧𝐞 𝐅𝐮𝐞𝐥 𝐂𝐞𝐥𝐥 , the first article published by Michal that, reveals why controlling potential limits is critical to prolonging the life of a hydrogen fuel cell.

Abstract

Octahedra (oh) PtNiX/C catalysts are notable cathode catalysts for proton-exchange membrane fuel cells due to their exceptional oxygen reduction reaction activity. Here, we investigate the degradation of oh-PtNiIr catalysts under fuel-cell conditions using operando X-ray diffraction (XRD). Employing two accelerated stress tests with different lower potential limits and XRD-coupled cyclic voltammetry on benchmark Pt and oh-PtNiIr catalysts, we find that dissolution and degradation are proportional to the extent of reduction, independent of the catalyst’s nature. Our method identifies the optimal potential range for Pt-based catalysts to minimize degradation without lengthy stress tests.

, Michal Ronovsky, Lujin Pan, Malte Klingenhof, Isaac Martens, Lukas Fusek, Peter Kus, Raphael Chattot, Marta Mirolo, Fabio Dionigi, Harriet Burdett, Jonathan Sharman, Peter Strasser, Alex Martinez Bonastre and Jakub Drnec* , ACS Appl. Energy Mater. 2023, 6, 17, 8660–8665. Publication Date: August 31, 2023 https://doi.org/10.1021/acsaem.3c01243

Congrats to Michal, all the collaborators and the project partners for their valuable contribution to this achievement!

Text by Chiara Facoetti