Nanostructured Cobalt@Shell catalysts for an optimized product spectrum in the Fischer-Tropsch synthesis
FacultiesFakultät für Naturwissenschaften
InstitutionsInstitut für Chemieingenieurwesen
External cooperationsKarlsruher Institut für Technologie
Cobalt-based catalysts used in LTFT show a high selectivity towards long chain hydrocarbons, mainly waxes. For the production of short-chain products like gasoline the typical FT selectivity needs to be shifted. The connection of FT and HP reaction predominantly results in the direct production of liquid fuels. This is possible via the introduction of a second catalytic function either on the reactor scale by the combination of two different catalyst materials, one active for FT and the other for HP, inside the same reactor, or on the particle scale by the direct synthesis of catalyst particles with both catalytic functions in local proximity, which is even more beneficial. The most promising material class are core-shell materials, which offer a stabilization of cobalt particles against sintering in the core, while the tunable architecture of the shell influences the residence time of educts and products inside the particle as well as the local educt concentration. The nanostructured catalyst materials in particular provide short diffusion lengths and thus reduced mass transport issues. Furthermore, the bottom-up synthesis approach allows an adjustment of the cobalt particle size and the tunability of the support properties, rendering them as interesting candidates for further investigations. Therefore, the overall objective of this thesis is the investigation of cobalt@shell catalysts, which can be used for the direct production of liquid fuels from biomass in decentralized production plants via a combined FT and HP process.
Subject HeadingsFischer-Tropsch-Synthese [GND]