Composite resins for 3D printing of corundum and corundum-kaolin based monoliths for catalytic applications

• Published in: Ceramics international 2023-01, Vol.49 (2), p.1902-1910
• Main Authors: Nowakowska, Marcelina, Rokicińska, Anna, Kuśtrowski, Piotr, Michorczyk, Piotr
• Format: Article
• Language: English
• Subjects: 3D printing; Al2O3; Composites
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2022.09.155

Several composite organic-inorganic resins dedicated to 3D printing using Digital Light Processing (DLP) technology containing nano- and micro-structured corundum as well as corundum/kaolin mixtures were prepared and characterised in terms of their rheology and stability. Using these resins, short monoliths were printed using the DLP technology at a resolution of x:y:z = 30/30/50 μm. After thermal pre-treatment, the printed materials were studied by X-ray fluorescence (XRF), X-ray diffraction (XRD), and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). Based on the selected monoliths, MnOx- and Na2WO4-containing catalysts were prepared by two-step impregnation and tested in the oxidative coupling of methane (OCM) at 820 °C using a ratio of methane/oxygen of 3.8/1. The maximum conversion of methane (28%) and total conversion of oxygen (100%), as well as stable selectivity to ethane (22%) and ethylene (44%), were achieved using three short monoliths (GHSV = 7676 h−1). A further enhancement of the number of monoliths influenced only the COx and C3 selectivity. Moreover, a comparative study of monolithic and powder samples with identical compositions revealed that for the monolithic catalyst the yield of C2–C3 hydrocarbons is slightly lower (1–2%) but at a 3–4 times lower pressure drop.