초록 |
Self-pillared pentasil (SPP) comprised of MFI layers has been synthesized with differing Si/Al ratios and mesoporosities. After that, Cu was impregnated on these SPP particles in order to use as a hydrocarbon trap (HC trap). The resulting Cu-SPPs could not only adsorb HCs, but also oxidize HCs at relatively low temperature even in the presence of 10 vol% vapor. Within these Cu-SPPs, the sample which has Si/Al ratio of ∼22 and medium mesoporosity exhibited highest performance in cold-start tests. The preferred adsorption can be attributed to the larger amount of exchanged Cu2+ ions in SPPs with a lower Si/Al ratio, while the oxidation was due to the small CuO particles attached on the SPP surface. However, the aging test showed that the zeolite structure in the Cu-impregnated SPPs was ruined and transformed into another phases, thus dramatically decreasing adsorption ability. Nevertheless, the oxidation performance by CuO particles was still sustained. |