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Project

Advanced solid state NMR methods for dealing with paramagnetism and short range disorder in catalytic materials.

NMR spectroscopy is one of the most powerful tools for structural and functional analyses of materials, especially if supported by quantum-chemical computations and modelling. Here we shall extend the applicability of solid state NMR to paramagnetic catalysts and to heterogeneous, disordered catalysts. Using a set of Cu-containing MOFs as test cases, we shall optimize NMR measurements and first-principles calculations of paramagnetically-induced NMR shifts, thus outlining an approach for reliable assignment of the NMR signals in such paramagnetic samples. Using our approach, we will study Cu-catalyzed dehydrogenative cross-coupling of alkynes and arenes in a porous Cu catalyst. Combined NMR and quantum-chemical calculations will identify the reaction intermediates and elucidate the formation of arylalkynes. In the second part, the distribution of catalytic sites in MOFs and zeolites will be inspected by the spin-diffusion-based NMR approach. In the UiO-66 MOF, the catalytic sites will be missing linker defects, whereas in zeolites they will be Brønsted and Lewis acid sites. The missing linker defects and the Lewis sites will be decorated with organic probes, and a combined NMR/modelling approach will be used to inspect the proximity between these probes in the MOFs, or between the probe molecules and the Brønsted sites in zeolites. The gained information about the distribution of active sites will be of paramount importance for the design of new catalysts.
 

Date:1 Jan 2018 →  31 Dec 2021
Keywords:NMR spectroscopy, paramagnetism and short range disorder in catalytic materials, structural and functional analyses of materials
Disciplines:Condensed matter physics and nanophysics, Analytical chemistry, Macromolecular and materials chemistry, Inorganic chemistry, Theoretical and computational chemistry, Other chemical sciences