骨架富含Si(4Al)结构的SAPO-34分子筛的合成及其对甲醇制烯烃反应的催化性能  

Synthesis of SAPO-34 with Rich Si(4Al) Coordination Environment in the Framework and Its Catalytic Performance in Methanol-to-Olefins Reaction

作　　者：许磊[1] 杜爱萍[1] 魏迎旭[1] 孟霜鹤[1] 何艳丽[1] 王莹利[1] 于政锡[1] 张新志[1] 刘中民[1] 

机构地区：[1]中国科学院大连化学物理研究所

出　　处：《催化学报》2008年第8期727-732,共6页

摘　　要：通过在初始凝胶中加入HF合成了骨架富含Si（4AI）配位结构的SAPO-34分子筛。使用X射线衍射、扫描电镜、X射线荧光和核磁共振等表征手段研究了初始凝胶中HF的加入对合成SAPO-34分子筛的晶体结构、晶体形貌、元素组成以及骨架硅配位环境的影响结果表明，在初始凝胶中加入F离子后，合成的SAPO-34分子筛的晶体结构更加规整；随着初始凝胶中F离子含量的提高，合成的SAPO-34分子筛晶体骨架中Si（4AI）配位结构的数量增多，Si（n／AI）（n=3～0）配位结构的数量减少。将合成的SAPO-34分子筛催化剂用于甲醇制烯烃反应，结果显示，SAPO-34分子筛骨架中富含Si（4AI）配位结构可以有效提高反应产物中乙烯的选择性，同时能够延长催化剂的寿命。SAPO-34 molecular sieve samples with rich Si（4AI） coordination environment were synthesized by adding HF in the initial gel. The crystalline phase, crystal morphology, elemental composition, and Si coordina-tion environment of the as-synthesized samples were determined by means of X-ray diffraction, scanning electron microscopy, X-ray fluorescence spectroscopy, and nuclear magnetic resonance. The crystallization of SAPO-34 molecular sieve can be adjusted by adding HF in the initial gel, and correspondingly, the Si coordination modeling can be controlled. The proportion of Si（4AI） species in the as-synthesized SAPO-34 increased, and that of Si （hAl） （n = 3-0） decreased with increasing fluorine ion content in the initial gel. The catalytic performance of the SAPO-34 catalysts with various Si coordination was investigated in the methanol-to-olefins reaction. The re-sults showed that SAPO-34 catalysts with rich Si（4AI） coordination structure had higher selectivity to ethylene and longer life time.

关 键 词：SAPO-34分子筛 氟化氢 Si(4AI)结构 甲醇制烯烃反应 

分 类 号：O643.32[理学—物理化学]