(532cy) Cu Loaded Hierarchical MFI Zeolite Synthesis and the Effect of Its Physicochemical Properties As Hydrocarbon Trap during Cold Start Test

Self-pillared pentasil (SPP), comprised of thin MFI layers as lamellar structure, has been synthesized with varying mesoporosities and Si/Al ratios. For the purpose of adjusting as hydrocarbon trap (HC trap), Cu was impregnated on the synthesized SPP particles. The resulting Cu-SPPs could not only adsorb HCs at 70 °C, but also oxidize HCs at relatively low temperature even in the presence of 10 vol% vapor. The hydrocarbon adsorption can be attributed to the larger amount of exchanged Cu²⁺ ions in SPPs with a lower Si/Al ratio, on the other hand, the oxidation was due to the small CuO particles attached on the SPP surface. However, after hydrothermal treatment, the structure of SPPs transformed into unwanted phases, consequently losing adsorption capacity. Nevertheless, the oxidation ability by small CuO particles was still maintained.