| 초록 |
The Cu-BEA zeolites are prepared with various Cu amounts. All Cu-BEA zeolites are effective for adsorbing and low-temperature oxidizing hydrocarbons (HCs; propene and toluene) in cold-start test (CST) and, especially, 5 wt.% of Cu loaded BEA zeolite shows marked performances. To achieve high efficiency during cold start period, preferential adsorption of propene and low temperature oxidation of HCs are needed. We found that the amount of Cu+ ions are highly related to the adsorption amount of propene and small (ca. 1-2 nm) CuO particles at the surface of HC trap could lower the temperature of oxidation. Finally, hydrothermal treatment at 800 °C with varying time (3-24 h) was used to test long-term stability of HC trap; the CST performance revealed that the adsorption ability for propene was dramatically decreased with time increasing, but for toluene, along with the oxidation ability, were still maintained. |
