Lecture
Van Marum Colloquium: Watching nanoparticles in action: Characterization of electrocatalysts with synchrotron X-ray techniques
- Date
- Monday 16 October 2023
- Time
- Location
-
Gorlaeus Building
Einsteinweg 55
2333 CC Leiden - Room
- DM0.13
Abstract
Electrocatalysis plays a major role in energy conversion technologies such as electrolyzers and fuel cells. Small nanoparticles, typically less than 10 nm in size, provide a high surface-to-bulk-atom ratio which is crucial for efficient utilization of the catalyst material, often based on scarce precious metals like Pt[1] and Ir.[2] However, these small nanoparticles suffer often from instability in electrochemical environments, and the underlying degradation mechanisms are, so far, not fully understood. In this context, synchrotron X-ray techniques are valuable tools for unraveling the catalyst's structural changes during operation. In-situ and operando experiments enable us to monitor the evolution of atomic structures. With small-angle X-ray scattering (SAXS), changes in size and morphology can be tracked,[3] while X-ray diffraction provides insights into the crystalline atomic structure.[1] This can provide valuable information on the mechanisms that dominate catalyst degradation and can help to devise new strategies for stability optimization.[4] I will focus on the strengths and limitations of the different operando scattering techniques, SAXS, XRD, and X-ray total scattering, and how they can be combined, also with X-ray absorption spectroscopy (XAS). This integration offers a complete picture of the catalyst structure at applied potentials, which is fundamtal for establishing structure-property relations.
References
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- A. Bornet, R. Pittkowski, T. M. Nielsen, E. Berner, A. Maletzko, J. Schröder, J. Quinson, J. Melke, K. M. Ø. Jensen, M. Arenz, ACS Catal. 2023, 7568–7577.
- J. Schröder, R. K. Pittkowski, J. Du, J. J. K. Kirkensgaard, M. Arenz, J. Electrochem. Soc. 2022, 169, 104504.
- J. Du, J. Quinson, D. Zhang, B. Wang, G. K. H. Wiberg, R. K. Pittkowski, J. Schröder, S. B. Simonsen, J. J. K. Kirkensgaard, Y. Li, S. Reichenberger, S. Barcikowski, K. M. Ø. Jensen, M. Arenz, JACS Au 2022, 2, 1757–1768.