3D printed catalytic converters with enhanced activity for low-temperature methane oxidation in dual-fuel engines

Catalytic converters with non-linear channel structures were prepared using 3D printing and tested in the oxidation of methane in a simulated dual-fuel engine exhaust stream. The design used a simple repeating angular offset between adjacent layers, which was sufficient to introduce complexity with minimal software programming. All 3D printed substrates were mechanically stable and, following washcoating with a composite catalyst, demonstrated higher catalytic activity in methane oxidation than a commercial honeycomb substrate. The methane conversion at e.g. 510 °C was 12.6% on the commercial sample, 72.6% for 90 °, 80.1% for both 30 ° and 45 °, and 89.6 % for the 60 ° oriented structures. This enhancement is attributed to the increased turbulence/mass transfer and surface area than are possible using conventional straight-channelled substrates. Computational fluid dynamics (CFD) analysis confirmed that the higher methane conversion over 3D printed substrates is due (at least partially) to its higher turbulence kinetic energy. Backpressures over the 3D printed structures were also experimentally measured and compared with the conventional honeycomb monolith