The Interdisciplinary Colloquium offers (young) scientists at the University of Koblenz the opportunity to present themselves and their research projects to a broad university public and to engage in conversation, get to know each other and exchange ideas. The scientific topics of the talks are presented in a comprehensible way and made accessible across disciplines in order to contribute to the scientific culture on campus.
Chemical processes for the production of biofuels, fertilizers, pharmaceuticals, or for environmental remediation of greenhouse gas emission, rely mostly on the use of catalytically active metal nanoparticles dispersed on oxide supports. These metallic nanoparticles represent the active sites in the heterogeneous reactions that are necessary for these productions. Because of their large surface area and reactivity, they enable high reaction rates and process efficiency. Traditionally, catalysts are prepared by deposition of the nanoparticles on oxide supports using impregnation methods. In general, catalysts prepared by these methods tend to lose their activity when used at high temperature. This is because the nanoparticles are loosely bonded to the support, making them to easily migrate over the surface of the support, thus leading to coalescence, sintering and subsequent deactivation during high-temperature and prolonged operation. However, to overcome these drawbacks, exsolution method (Figure 1) has proven to be a novel concept for the preparation of a more efficient and durable metal catalysts by growing them directly from the oxide support at elevated temperature. Such exsolved catalysts display a high stability against sintering and coking, since they are partially submerged in the host oxide support, contrary to the deposited particles. In this project, we want to understand how exsolution occurs to enable us to tune the size, shape and composition of the exsolved nanoparticles with the aim of designing highly optimised and smart catalysts.
Figure 1. Schematic illustration of metallic nanoparticles on oxide supports prepared by impregnation and exsolution methods.
In cooperation with the CZS MINT-Forum.
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