Watching nanoparticles in action: Characterizing electrocatalysts with synchrotron X-rays

e-CHEMS lecture Rebecca Pittkowski

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We are happy to invite you to the upcoming e-CHEMS lecture on Thursday, October 17th, from 15:00, for a lecture by Rebecca Pittkowski from the University of Copenhagen. In the lecture, she'll delve into the topic of 'Watching nanoparticles in action: Characterizing electrocatalysts with synchrotron X-rays'.

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 frequently from instability in electrochemical environments, and the underlying degradation mechanisms and structural rearrangements are, so far, not fully understood.[3] 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,[1] while X-ray total scattering with PDF analysis provides insights into the atomic structure.[4] This can provide valuable information on the mechanisms that dominate catalyst degradation and help devise new strategies for stability optimization. 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 with X-ray absorption spectroscopy (XAS). This integration offers a complete picture of the catalyst structure at applied potentials, which is fundamental for establishing structure-property relations.

Short Bio

Rebecca Pittkowski is a tenure track assistant professor at the Department of Chemistry at the University of Copenhagen. She studied Chemistry (BSc. and MSc) at TU Dresden, Germany. In her PhD, she worked with Prof. Petr Krtil at the J. Heyrovsky Institute of Physical Chemistry, Czech Academy of Sciences, in Prague as a PhD fellow in the Marie Curie International training network “Elcorel”. After graduating from the University of Chemistry and Technology in Prague in 2020, she worked as a postdoc at the University of Bern with Prof Matthias Arenz and at the University of Copenhagen with Assoc. Prof. Kirsten Jensen and Prof. Jan Rossmeisl. She started her own group at the University of Copenhagen in 2023. Her research concerns nanoparticle electrocatalysis and focuses on operando studies of electrocatalysts using synchrotron X-ray absorption spectroscopy and X-ray scattering techniques.

Start date and time
End date and time
Location
David de Wied Building, M2.01
Entrance fee
Free