无机材料学报 ›› 2021, Vol. 36 ›› Issue (1): 101-106.DOI: 10.15541/jim20200059

• 研究快报 • 上一篇    下一篇

活化晶种调节SAPO-34的性质及其对甲醇制烯烃反应催化寿命的增强

张栋强,路惠惠,苏娜,李贵贤,季东,赵新红   

  1. 兰州理工大学 石油化工学院, 兰州 730050
  • 收稿日期:2020-02-08 修回日期:2020-03-28 出版日期:2021-01-20 发布日期:2020-06-09
  • 作者简介:张栋强(1981-), 男, 副教授. Email:zhangdq@lut.edu.cn

Modulation of SAPO-34 Property with Activated Seeds and Its Enhanced Lifetime in Methanol to Olefins Reaction

ZHANG Dongqiang,LU Huihui,SU Na,LI Guixian,JI Dong,ZHAO Xinhong   

  1. School of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou 730050, China
  • Received:2020-02-08 Revised:2020-03-28 Online:2021-01-20 Published:2020-06-09
  • About author:ZHANG Dongqiang(1981-), male, associate professor. E-mail:zhangdq@lut.edu.cn
  • Supported by:
    National Natural Science Foundation of China(21666018);National Natural Science Foundation of China(21666019)

摘要:

无溶剂法合成沸石法在多个方面优于常规水热合成法, 近年来引起广泛关注, 但是采用该方法合成的微孔SAPO-34沸石催化剂的催化寿命较短, 无法满足甲醇制烯烃工业应用的要求。本研究中开发了一种改良的无溶剂法, 使用该法合成了具有优异甲醇制烯烃反应性能的SAPO-34催化剂。该法在合成体系中引入酸活化晶种, 通过调节沸石晶化动力学来调控催化剂的物理化学性质。采用不同技术对无溶剂法合成的系列SAPO-34催化剂的结构性质进行了分析表征。结果表明:与未引入晶种合成的父代样品相比, 添加晶种得到的子代SAPO-34样品具有更高的结晶度、比表面积及低的强酸中心密度, 对甲醇制烯烃反应的催化寿命可延长到480 min, 远远优于对应的父代样品(40 min)。这一结果证实了无溶剂合成中晶种的使用可有效调节沸石的性质, 可见该方法在提高沸石催化性能方面具有巨大潜力。

关键词: SAPO-34沸石, 甲醇制烯烃反应, 无溶剂合成, 活化晶种

Abstract:

Solvent-free synthesis of zeolites has received extensive attention in recent years, because it is advantageous over conventional hydrothermal synthesis. Nevertheless, SAPO-34, a micropore zeolite, prepared by this method does not satisfy the catalytic lifetime requirements of the methanol-to-olefins (MTO) reaction. Herein, an improved solvent-free approach was developed to synthesize SAPO-34 catalysts with enhanced MTO reaction performance, in which acid-etched seed crystals were introduced to modulate the physico-chemical properties of the zeolite via crystallization kinetics regulation. The results indicated that the SAPO-34 samples prepared from seed-containing precursor gels show considerably higher crystallinity, larger surface area, but lower strong acid site density than the parent sample. In particular, the catalytic lifetime of the SAPO-34 catalyst prepared from activated seeds was remarkably prolonged to 480 min, which was significantly superior to that of the parent sample (40 min). The result confirmed the validity of the seeding approach for modifying the zeolite properties via the solvent-free synthesis and the potential of the approach in improving catalytic performance.

Key words: SAPO-34, methanol to olefins reaction, solvent-free synthesis, activated seeds

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