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Spatio-Temporal Dynamics of Oscillatory Heterogeneous Reactions Studied by Multi-Scale in Situ Electron Microscopy

Update time:Oct 24, 2018

Speaker:Prof. Willinger Marc Georg,Swiss Federal Institute of Technology Zurich
Time:Tuesday,10:00a.m.,25th October
Place:A718

Abstract :
To date, improvement of catalysts in terms of activity, selectivity and lifetime, as well as the search for alternative catalyst materials with reduced content of rare-earth metals is mostly guided by chemical intuition. During the last years, they have used a combination of in situ TEM and in situ SEM to study catalyst dynamics on different scales. By bridging the scale from the to the mm range and pressures from 10-5 to 10+3 Pa, they are able to reveal the dynamic nature of active catalysts. It will be shown that simultaneous detection of reaction products by RGA enables correlating structural dynamics with catalytic activity. They observe rate oscillations and oscillatory behaviour that is inherent to the action of a catalyst: it has to break bonds and facilitate the formation of new bonds over and over again. Modulation of the catalyst and alteration of its interaction with the gas-phase, as well as reaction induced changes in temperature and surface coverage serve as feedback mechanism for the induction of oscillatory behavior at different scales and formation of complex spatiotemporal pattern. Since the outset of UHV surface science studies, legitimate concerns have been raised regarding whether a pressure gap and/or a materials gap exist that would make studies at low pressure on model systems irrelevant for the high-pressure world of industrial catalysis. With their multi-scale approach, they hope to be able to bridge the materials and pressure gap.

Short Bio :
Willinger Marc Georg now is an associate professor of Scientific Center for Optical and Electron Microscopy ScopeM, ETH Zürich. From 2011 to 2018, he was a group leader of the “Electron Microscopy” at the Department of Inorganic Chemistry of the Fritz Haber Institute of the Max Planck Society in Berlin. And from 2015 to 2017, associate prof. Willinger Marc Georg worked in department of Colloid Chemistry at the Max Planck Institute for Colloids and Interfaces in Potsdam. From 2006 to 2011, he was an independent researcher at the University of Aveiro. In 2006, associate prof. Willinger Marc Georg was awarded with the Schering-Price for the best PhD in chemistry in 2005. Now, associate Prof. Willinger Marc Georg has published more than 140 in peer reviewed journals. And his H-Index is 31.


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