杂原子沸石的二次合成及其表征——Ⅲ.含镓ZSM-5

The Secondary Synthesis of Zeolite via Framework Substitution for Aluminum Ⅲ. Preparation and Characterization of Zeolite ZSM-5 Containing Ga

以HZSM-5为原料,(NH_4)_3GaF_6为取代剂。进行液-固相同晶取代反应,制备出骨架含Ga的[Ga]ZSM-5沸石,并用化学分析、IR、XRD、等多种方法进行了表征。[Ga]ZSM-5沸石的结晶度保持良好,空穴浓度几无改变,有一部分Ga处于骨架外,不为稀盐酸所交换。Ga进入ZSM-5沸石后,其晶胞参数增大,表面酸性发生变化。试验表明骨架含Ga的[Ga]ZSM-5比阳离子位含Ga的GaZSM-5对于正已烷反应,具有更好的芳构化选择性。

A new method for produ ing highly orystalline zeolite [Ga]ZSM-5 by isomorphons substitution between ZSM-5 and(NH)_(?)GaF_(?) is reported. A series of measurements including chemical analysis. (?)R. XRD have been taken. The[Ga]ZSM-5 zeolite retains a good orystalinity and there is no change in cavity con(?)entr(?)tion. Some gallium cations are (?)ted outside of the tramework, which are not exchanged (?) 0.1mol/] HCl acid tra(?)ment. It is also tound that the incorporation of [Ga]into zeolite ZSM-5 (?)eads to an increase in unit cell parameter and difference in surtace acidity. In the (?)onversion ot hexane into aromatic hydrocarbon, [Ga] ZSM-5 pre-ents higher se(?)ectivity toward aromatics than[Ga] ZSM-5, in which[Ga] isthe cation.