• Vippola, Minnamari
• Vastamäki, Teemu
• Levänen, Raimo Erkki
• Honkanen, Mari Hetti
• Zakeri, Setareh
• Järveläinen, Matti

Abstract

<p>Despite increasing interest in the use of alternative fuel, conventional diesel or gasoline powered vehicles still dominate road transportation; removal of their emitted pollutants is a challenge to sustainable transportation. The automotive industry has employed catalytic converters (CCs) to effectively modify or eliminate toxic pollutants emitted by combustion engines. The efficiency of a CC greatly depends on its geometry and is hindered by limitations in fabrication techniques. To go beyond these limits and further enhance the performance of CCs, one can use state-of-the-art ceramic stereolithography (CSL) technology, which enables fabrication of complex-shaped structures. In this work, a novel photocurable ceramic resin made of γ-Al₂O₃ and CeO₂ (the commonly used washcoat materials in CCs) is shaped into the honeycomb and twisted honeycomb structures using CSL. Measurements reveal that upon the addition of CeO₂ to the plain γ-Al₂O₃ resin, the penetration depth of light is significantly decreased from 408.06 μm to 75.19 μm. This research also focuses on the balance between having a high surface area and achieving good physical stability in the printed structures. Accordingly, the appropriately debinded structures are sintered at two different temperatures: 900 °C and 1100 °C. It is found that the structure sintered at 900 °C has a higher surface area, and thus, it is a better candidate for catalytic applications. Furthermore, investigation of the stabilizing effect of CeO₂ on printed γ-Al₂O₃ finds that CeO₂ is effective in stabilizing the printed γ-Al₂O₃ at1100 °C but not 900 °C. Targeting the realization of green and sustainable transportation, the applied CSL technique in this study enables flexible control in the design and fabrication of self-supporting structures that are expected to open promising ways for the optimization of CCs.</p>

Topics

• impedance spectroscopy
• surface
• combustion
• ceramic
• resin