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Prof. Bert Weckhuysen
Bert M. Weckhuysen, Inorganic Chemistry and Catalysis group, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands; [email protected]
Thursday, February 27th, 2020, room 1315 3:30 pm Spectroscopy and Microscopy of Solid Catalysts: A Tutorial Lecture on Catalyst
Characterization and Related Challenges & Opportunities
The search for new or more effective solid catalysts would benefit when we could bridge the molecular world with the macroscopic world. Such detailed information can be realized if we would have access to a very powerful camera shooting molecular movies of an active catalytic solid at the levels of single atoms and molecules under true reaction conditions, i.e., high temperatures and pressures. This is the field of in-situ and operando spectroscopy and recent breakthroughs in characterization techniques, based on optical, electron and X-ray methods, demonstrate that such molecular movie concept is within reach. This tutorial lecture provides an overview of the different methods available for catalyst characterization. I will discuss recent advances in spectroscopy and microscopy of catalytic solids at different length scales, starting from single molecules and single atoms up to the level of individual catalyst particles (Figure 1). Examples of spectroscopic techniques, exploring the “nanoworld” of solid catalysts, to be discussed include single-molecule fluorescence microscopy, X-ray tomography, transmission electron microscopy, nano-IR spectroscopy, shell-isolated nanoparticle-isolated Raman spectroscopy and tip-enhanced Raman spectroscopy. We will discuss the intrinsic requirements, design and construction of valuable operando measurement cells for investigating catalytic solids at work. Another important aspect to be highlighted in this lecture is related to proper data analysis/mining when dealing with large data sets; something what is especially important when considering e.g. tomographic reconstructions, as well as when exploring the time domain.
Figure 1. Heterogeneous catalysis as a multiscale science and technology, in which the macroscopic world of catalytic activity, selectivity and stability as measured in a catalytic reactor connects via the mesoworld with the nanoworld of individual atoms and molecules within a single catalyst particle. Operando spectroscopy of a catalytic solid should enable us to create a “Google earth” camera viewing the working catalyst, including both the organic and
Casey Lectures
inorganic part of chemical processes, at different length scales, which enables to capture the reactants, reaction intermediates and reaction products of the catalytic cycle.
