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Abstract

This thesis investigates the potential of acetylene to make a comeback as a platform molecule for the chemical industry, especially towards the production of C 4 compounds. The rich history of this compound and its various known reactions are reviewed in the introduction.
Because of the special cautions required in order to manipulate pressurized acetylene, some safety aspects of handling it are introduced. In order to safely conduct experiments with acetylene at elevated pressures we have built a versatile setup, which offers the possibility to investigate both batch and flow reactions with pressurized acetylene, and a thorough description of this setup is offered.
The energy-rich nature of acetylene gives rise to some difficulties when trying to develop catalytic processes for its valorization. We discuss the difficulties which we encountered with our batch and flow systems using molecular and solid catalysts, as these can serve to prepare future researchers on this topic for the challenges which are involved.
In our investigations of batch reactions with molecular catalysts, we have discovered the possibility to convert acetylene and ethylene to butadiene using ruthenium carbene based metathesis catalysts, the particularities, highlights and limitations of this system are discussed.
Using solid catalysts in a flow system we have developed a process for converting acetylene and hydrogen to butenes, ethylene, and various compounds with an even number of carbon atoms, which can reach butene productivities of over 2 g*g_cat^-1 *h^-1 . This is the first process using pressurized acetylene in the gas phase with a solid catalyst to produce butenes and also represents the very rare case of a detailed study about the behavior of pressurized acetylene with solid catalysts.