Characterization of 3D-printed ¿-Al2O3 used for Catalytic Applications

Abstract

In recent years, additive manufacturing (AM) techniques have made significant progress by increasing printing quality, the variety of printable materials, and 3D printer accessibility. In this sense, ceramic materials play a fundamental role due to their excellent properties such as high melting point, strength, corrosion resistance, low electrical and thermal conductivity, and chemical inertness. Due to its properties, it has a wide range of industrial and scientific applications. In this final Master`s project, gamma-alumina (γ-Al2O3) characterization has been performed to determine properties that are the best fit for Catalytic Applications. The microstructural and mechanical properties of the feedstock powder was studied using Cold Isostatic Pressing (CIP) and developing different thermal treatments (T.T) to optimize and be able to determine the sintering temperature (450 and 600 ºC). On the other hand, ceramic inks with different charges from 20 to 35 weight % were mixed with 25 weight % of Pluronic F-127®. The parts were 3D printed using cube and rectilinear geometries with 100 and 50 % infill, respectively. The density and the Vickers hardness of the material have been measured and compared between the CIP samples and the 3D printed samples. Finally, catalysis reactions to obtain ethylene through ethanol dehydration were carried out at temperatures from 200 to 600 ºC by using the 3D printed catalysts. Macro- and microstructural defects of printed parts were determined, such as the shrinkage after sintering, resulting between 10 and 12 % depending on the ceramic charge. The porosity was also measured to compare the impact of this defect on the catalytic experiment. Catalysis experiments have shown dehydration of ethanol. The catalyst sintered at 600 ºC has shown better performance in the reaction and the formation of the different products obtained from the reaction.