(134b) Design, Synthesis, and Catalytic Testing of 3D-Printed Fischer-Tropsch Catalysts

Fischer-Tropsch synthesis (FTS) is a strategically significant reaction to produce high-value liquid chemicals and hydrocarbon fuels from synthesis gas. Optimizing industrially favorable processes, such as FTS, remains challenging in catalysis. As a complex surface polymerization reaction, FTS highly depends on process conditions and catalyst behavior. Its product distribution and deactivation rates have been identified as functions of catalyst temperature, with hot spots leading to undesirable sintering and rapid deactivation. Historically, the preferred support for Fischer-Tropsch catalysts has been titanium dioxide (TiO₂), with metals such as iron, cobalt, and ruthenium comprising the active phase. In this work, we design, synthesize, and test novel FTS catalysts, focusing on designing support materials with improved heat transfer properties. A method using additive manufacturing (3D printing) based on direct metal laser melting (DMLM) is introduced alongside extensive CAD prototype modeling to develop thermally-conductive catalytic supports. A two-step electrochemical anodization process is used to develop TiO₂ nanotube arrays on the Ti-based supports. Different annealing processes for optimizing these nanotubular arrays are also assessed. Bimetallic FeCo-based catalysts (2.0 wt. %) are synthesized on the TiO₂ nanotubular arrays by a modified incipient wetness impregnation method.

The performance of the catalysts are measured using online gas chromatography-mass spectroscopy. Field-emission scanning electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy assisted in characterizing their morphology, elemental composition, and microstructures at different stages. The results obtained by the characterization of these materials show that the methods presented in this work for synthesizing novel FTS catalytic supports are successful. The bimetallic FeCo catalysts exhibit catalytic activity, and their performance is correlated to their structure. By presenting these novel methods for catalyst synthesis, this work poses a pioneering approach to three-dimensional structured catalyst design to optimize FTS.