MRCAT

The development of more efficient catalysts in terms of activity, selectivity, and stability is one of the key challenges today because of the need to optimize the use of resources within the context of a more sustainable development. In the search for more efficient chemical processes, one key approach consists in having a precise understanding of the structure of the active sites of the catalyst. This enables structure-activity relationships to be deduced, allowing for the rapid and rational development of catalysts with improved properties. Therefore, the use and the development of spectroscopic methods are essential because they can provide information on the electronic states and the structures of the active sites, which in turn provide the necessary molecular information for structure – activity relationship. Over the very recent years, paramagnetic NMR, DNP-enhanced NMR spectroscopy and EPR find themselves propelled as three of the most powerful techniques for the atomic-scale characterization of surface molecular species in functional materials, including catalytic systems. While a number of examples have shown that can complement infrared (IR), Raman, UV-Vis and X-ray absorption (XAS) along with other surface science and molecular modeling techniques, a number of challenges remain however to be solved before these magnetic spectroscopies are ready to cope with the detailed structure elucidation of active sites in heterogeneous paramagnetic organometallic catalysts. This research proposal concerns the development of innovative paramagnetic solid-state NMR and EPR strategies for the determination of atomic level description of highly challenging, industrially relevant Ziegler-Natta catalytic systems, which are involved in the synthesis of highly ubiquitous commodity polymers: polyolefins and which present paramagnetic centers, making the use of classical spectroscopic approaches nearly impossible. This 36-month project brings together leading laboratories in magnetic resonance, polymerization and heterogeneous catalysis from France and Switzerland, and will combine methodological advances in high-resolution solid-state NMR and EPR spectroscopies with innovation in catalysis that will be applied to relevant industrial challenges in the field of polymer chemistry. The complementary expertise provided by the three joint research groups will be essential to the success of this ambitious project, which will lead to the understanding and improvement of catalytic reactions involved the polymerization of olefins. Despite its industrial relevance, this heterogeneous catalysis suffers from a lack of molecular understanding of its key features, hampering breakthrough innovation. This project is grounded on the fundamental development of novel NMR and EPR approaches dedicated to the understanding and improvement of Ziegler-Natta catalysis, and as such meets the ANR call “Défi de tous les Savoirs”.