Electron Microscopy group

Group leader: Thomas Lunkenbein

The Electron Microscopy group focuses on the structural understanding of heterogeneous catalysts and chemical energy converters, using state-of-the-art X-ray diffraction and electron microscopy methods. In doing so, we seek to uncover the differences between local and averaged structures and to understand their chemical relationship to catalysis. To this end, our methodological portfolio includes not only detailed X-ray diffraction analysis and chemical electron microscopy, but also operando and quasi in situ measurements for X-ray diffraction and electron microscopy.

 

In Africa, they say, many small people in many small places doing many small things can change the face of the world.

By analogy, smallest local deviations from the average structure, which can occur at many different sites of a functional solid, such as heterogeneous catalysts, influence the local chemistry, the formation of the active phase and thus its performance. Using state-of-the-art high-resolution transmission electron microscopy, we are attempting to identify these differences. Multi-scale quasi in situ and operando electron microscopy approaches further help us to better understand the structure of a working catalyst over several orders of magnitude from the nanoscale to the macroscale. (Operando) X-ray diffraction analysis for thin films and powder materials allows us to determine and catalysis-induced change in the averaged crystalline bulk structure and round out the structural understanding in a complementary way. From these investigations we can extract structural proposals, which we communicate to theory groups for functional modeling.