| 초록 |
Zeolite ZK-5 (KFI-type), the first synthetic zeolite, has a 3-dimensional channel system and a small pore (3.9 Å). The first synthesis of ZK-5 with BaCl2 was reported by Barrer, but extraframework Ba was hardly removed by ion-exchange of NH4+, which is highly unfavorable for catalytic use. In 1991, Verdujin et al. reported that small amount of Sr leads to the formation of ZK-5. This system has been most widely used for synthesis of ZK-5. However, the formation of some impurities and/or amophous phase remains as a problem. In this work, we synthesized pure ZK-5 without any impurity by interzeolite conversion method (i.e. from zeolite USY to ZK-5). Several characterization techniques such as XRD, N2 adsorption-desorption, NH3-TPD, 29Si-NMR and 27Al-NMR were conducted. Selective catalytic reduction of NOx by NH3 was performed to verify its potential use as a catalyst. |
