Advanced preparation method of monolithic catalyst carriers using 3D-printing technology

This paper investigates the possibility of producing monolithic catalysts for the degradation of aromatic volatile organic compounds by additive manufacturing technologies (3D-printing) using two different approaches. Stereolithography (SLA) was used to produce inert ceramic catalyst carriers and Fused Filament Fabrication (FFF) was used to prepare polymer composite monoliths with integrated catalyst. Optimal 3D-printing conditions were determined for both types of monoliths. Shrinkage of 14.3–16.0% in the x and y-axis directions, and 18.3–20.1% in the z-axis direction was observed for the ceramic catalyst carrier after heat treatment, while the mass decreased by 32.0–32.5%. To prevent bending and warping, it was found that the 3D-models must be placed perpendicular to the build platform during 3D-printing and flat on the surface during heat treatment to avoid stress fractures. For the other approach, which involved the production of monoliths with integrated catalysts, nine thermoplastic materials were tested to determine the most suitable polymer matrix for the production of filaments for the FFF. Four composite filaments with different mass fractions of TiO₂ (1%, 5%, 7.5% and 10%, wt.%) and Z-GLASS as a polymer matrix were prepared by extrusion process. The results showed that with the increase of TiO₂ content, the brittleness of the material increased, while no significant changes in thermal stability were observed. Although monoliths were successfully 3D-printed using both approaches, future work will focus more on the use of ceramic monoliths due to their thermal and mechanical stability.