| 초록 |
A self-pillared pentasil (SPP) structured zeolite comprised of MFI nanosheets has been synthesized in various Si/Al ratios and mesoporosities. And then, to use as a hydrocarbon (HC) trap, we further conducted copper impregnation on them. The resulting Cu-SPPs could not only adsorb HCs in the exit gas stream (with 10 vol.% of water vapor), but also oxidize HCs to CO and CO2. Especially, Cu-SPP (Si/Al: ~22) with medium mesoporosity exhibited very high performance in cold-start trap tests; desirably adsorbing propene and toluene and holding them up to higher temperatures even in the 10 vol.% H2O in the gas stream condition. The preferred adsorption can be attributed to the with larger amount of exchanged Cu2+ ions in SPP particles with a lower Si/Al ratio. However, Cu-SPPs were collapsed after the hydrothermal ageing test and transformed into another undesired phase, thus losing the HC adsorption ability. |
