h1

TY  - THES
AU  - Spitzner, Robin
TI  - Maßgeschneiderte molekulare Katalysatoren auf Cyclohexylbasis und Reaktionskonzepte für die Nutzung von CO<sub>2</sub> als C1-Baustein
PB  - RWTH Aachen University
VL  - Dissertation
CY  - Aachen
M1  - RWTH-2024-09269
SP  - 1 Online-Ressource : Illustrationen
PY  - 2024
N1  - Veröffentlicht auf dem Publikationsserver der RWTH Aachen University
N1  - Dissertation, RWTH Aachen University, 2024
AB  - This thesis deals with the development of reaction concepts and catalyst systems based on ruthenium and novel tripodal cyclohexylligands for the partial reduction of CO2 with molecular hydrogen. In the first chapter, a short introduction is given and the current situation of different economic sectors with regard to their CO2 emissions in the EU is examined in detail. The usage of CO2 as a C1 building block is identified as a possible approach for the sustainable transformation of the current fossil-based industry and the economic constraints and chemical challenges are discussed. Finally, the objective and structure of this thesis are presented. The second chapter deals with the synthesis and characterisation of catalyst structures based on tripodal cyclohexylligands and their ruthenium complexes. This novel lead structure will be investigated by varying the ligand backbone through the introduction of functional groups with different properties, so that structure-activity relationships of the catalysts can be revealed and discussed. In Chapter 3, the synthesised ruthenium complexes of the cyclohexylligands are used in the catalytic hydrogenation of CO2 to various products. In detail, the synthesis of dialkoxymethane, cyclic and linear acetals and finally the production of methanol are investigated in the order of the oxidation level of the central carbon atom. The cyclohexylbased catalysts are compared with the current state of the art based on important key values in selected transformations of CO2. Chapter 4 deals with the development of an immobilisation and recycling strategy for the catalyst system presented. The immobilisation of catalysts on solid polymer-based acid supports is investigated. This type of immobilisation is used in the synthesis of dimethoxymethane, cyclic and linear acetals and methanol. In detail, a so-called ionomer (Nafion NR50) is used for this purpose, which fulfils important requirements for easy separation and recyclability due to its interesting specific properties such as high Brönsted acidity, Lewis acidity and high stability.
LB  - PUB:(DE-HGF)11
DO  - DOI:10.18154/RWTH-2024-09269
UR  - https://publications.rwth-aachen.de/record/994433
ER  -