Controlling Metal Nanoparticle Exsolution on Oxides By External Drivers – Defects, Elastic Strain and Ion Irradiation

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• Professor Bilge Yildiz, Massachusetts Institute of Technology, Cambridge, USA.
• Thursday 25 January 2024, 16:00-17:00
• Goldsmiths 1 & https://zoom.us/j/96836714124.

If you have a question about this talk, please contact Julie Smith.

All are welcome! Refreshments provided - including cakes!

Exsolution is an effective approach to fabricating oxide-supported metal nanoparticle (electro-)catalysts via phase precipitation out of a host oxide. A fundamental understanding and control of the exsolution kinetics are needed to engineer the size, density and composition of exsolved nanoparticles to obtain higher catalytic activity toward clean energy and fuel conversion reactions, such as in solid oxide fuel and electrolysis cells. Since oxygen release via oxygen vacancy formation in the host oxide is behind oxide reduction and metal exsolution, we hypothesize that the kinetics of metal exsolution should depend on the kinetics of oxygen release. In this work, we probe the surface exsolution kinetics both experimentally and theoretically using thin-film perovskite oxide model systems, show its relation to the oxygen evolution kinetics, and tune it by external drivers including elastic strain and ion irradiation. Using both drivers, we couple to the formation of point defects and defect clusters, that serve as nucleation sites for nanoparticle exsolution. As a result, we can controllably tune size, density, composition and position of the exsolved metal nanoparticles. This finding can guide the design of exsolution electrocatalysts to advance the performance and durability of solid oxide electrochemical cells.

Bio Professor Yildiz received a BS in nuclear engineering from Hacettepe University in Ankara, Turkey, in 1999 and a PhD in nuclear science and engineering from MIT in 2003. She stayed at MIT to do postdoctoral research in electrochemistry and then moved to Argonne National Laboratory to investigate structure and chemistry of energy conversion materials. She returned to MIT to join the faculty of the Department of Nuclear Science and Materials Science in 2007. Professor Bilge Yildiz’s research focuses on laying the scientific groundwork to enable next-generation electrochemical devices for energy conversion and information processing, guiding the design of novel materials for applications such as brain-inspired energy-efficient computing, fuel cells, electrolytic water splitting, and solid-state batteries. Professor Yildiz’s approach combines computational and experimental analyses.

This talk is part of the Department of Materials Science & Metallurgy Seminar Series series.

This talk is included in these lists:

• Department of Materials Science & Metallurgy Seminar Series
• Goldsmiths 1 & https://zoom.us/j/96836714124
• Mats Sciences Lists

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