The synergy between substrate architecture of 3D-printed catalytic converters and hydrogen for low-temperature aftertreatment systems

This study proposes 3D-printed diamond-based lattice substrates as catalytic converters in the automotive aftertreatment system to improve vehicle cold-start emissions. The study aimed to compare the influence of 3D-printed diamond-based catalyst structures on the light-off behaviour compared to the conventional 400 Cell Per Square Inch (CPSI) honeycomb catalyst design in a real exhaust gas environment. Moreover, the benefits of H2 addition on the performance of advanced lattice structures are examined for the first time to further increase the low-temperature catalytic efficiency. Digital Light Processing (DLP) technology was effectively utilised to manufacture lattice structures with high cell density to allow a comparison between conventional and advanced geometry designs. Further, the 3D-printed substrates were catalyst coated, and their light-off behaviour was studied in a diesel exhaust environment. The results of the light-off showed a significant improvement in the light-off temperatures for CO, THC and NO in the 3D-printed lattice structures. Furthermore, H2 presence additionally enhanced the low-temperature activity of the AM lattice structures.