| 초록 |
The needs for reducing the emission of CO, NOx, and hydrocarbon have been increased because of the strict regulations. Below ~300 °C temperature region called cold start period, the oxidizing capability of three-way catalysts is so low that unburned hydrocarbon molecules are directly emitted to atmosphere. In this respect, a hydrocarbon trap is adopted to decrease the emission of hydrocarbon molecules. MFI type zeolite, especially ZSM-5, has been regarded as a promising hydrocarbon trap because of its proper pore size and affinity. We prepared two types of ZSM-5 zeolites having distinct cations, cation A- and B-form ZSM-5. Copper compounds were introduced to stated ZSM-5 particles. By using myriad methods of characterization, the states of copper located in Cu/Cation A-ZSM-5 and Cu/Cation B-ZSM-5 were demonstrated. Furthermore, the cold start tests were also practiced, and we obtained a conclusion that Cu/Cation B-ZSM-5 has good performance for removing hydrocarbon. |
