催化学报

催化学报 ›› 2008, Vol. 29 ›› Issue (8): 727-732.

• 研究论文 • 上一篇    下一篇

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

许磊1,2,杜爱萍1,魏迎旭1,孟霜鹤1,何艳丽1,王莹利1,2,于政锡1,2,张新志1,刘中民1   

  1. 1 中国科学院大连化学物理研究所, 辽宁大连 116023; 2 中国科学院研究生院, 北京 100049
  • 收稿日期:2008-08-25 出版日期:2008-08-25 发布日期:2012-06-20

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

XU Lei1,2, DU Aiping1, WEI Yingxu1, MENG Shuanghe1, HE Yanli1, WANG Yingli1,2, YU Zhengxi1,2, ZHANG Xinzhi1, LIU Zhongmin1*   

  1. 1 Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian 116023, Liaoning, China; 2 Graduate University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2008-08-25 Online:2008-08-25 Published:2012-06-20

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1107

被引次数

23

摘要： 通过在初始凝胶中加入HF合成了骨架富含Si(4Al)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(4Al)配位结构的数量增多, Si(nAl)(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(4Al)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.

关键词: SAPO-34分子筛, 氟化氢, Si(4Al)结构, 甲醇制烯烃反应

Abstract: SAPO-34 molecular sieve samples with rich Si(4Al) coordination environment were synthesized by adding HF in the initial gel. The crystalline phase, crystal morphology, elemental composition, and Si coordination environment of the as-synthesized samples were determined by means ofX-raydiffraction, scanning electron microscopy,X-rayfluorescence 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(4Al) species in the as-synthesized SAPO-34 increased, and that of Si(nAl)(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 results showed that SAPO-34 catalysts with rich Si(4Al) coordination structure had higher selectivity to ethylene and longer life time.

Key words: SAPO-34 molecular sieve, hydrogen fluorine, Si(4Al) coordination environment, methanol-to-olefins reaction