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化学学报
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化学学报 ›› 2008, Vol. 66 ›› Issue (19): 2099-2106. 上一篇    下一篇

研究论文

无粘结剂ZSM-5沸石催化剂骨架脱铝改性的研究

程晓维 汪 靖 郭 娟 龙英才*

  

  1. (复旦大学化学系 上海市分子催化与新材料重点实验室 上海 200433)

  • 投稿日期:2007-11-12 修回日期:2008-04-20 发布日期:2008-10-14
  • 通讯作者: 龙英才

Binder-free ZSM-5 Zeolite Catalysts Modified with Framework De-alumination

CHENG, Xiao-Wei WANG, Jing GUO, Juan LONG, Ying-Cai*   

  1. (Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry,
    Fudan University, Shanghai 200433)
  • Received:2007-11-12 Revised:2008-04-20 Published:2008-10-14
  • Contact: LONG, Ying-Cai

PDF

1880

被引次数

23

对比了无粘结剂和有粘结剂ZSM-5沸石催化剂的吸附性质, 证实前者的优良品质. 以27Al固体核磁共振(MAS NMR)考察了盐酸处理、水蒸气处理及水蒸气-盐酸相结合处理后无粘结剂ZSM-5沸石催化剂的骨架脱铝行为以及非骨架铝的状态. 以X射线粉末衍射(XRD), X射线荧光光谱(XRF), 低温氮吸附, NH3-TPD和吡啶吸附原位红外光谱(in situ IR)等详细表征了骨架脱铝对其晶体、元素组成及孔结构、表面强(S)酸与弱(L)酸、Brönsted(B)酸与Lewis(L)酸酸量分布等影响. 揭示了水蒸气处理的深度骨架脱铝强烈地调变沸石的结构和表面酸性的本质, 证明了该处理方式对调变S酸和B酸起主导作用.

关键词: ZSM-5沸石, 催化剂, 无粘结剂, 骨架脱铝, 酸性质

The adsorption properties of binder-free and binder-containing ZSM-5 zeolite catalysts were compared, and the former one was proved to possess the excellent properties. The binder-free ZSM-5 zeolite catalyst has been treated with HCl solution, steaming, and steaming combined with HCl solution, respectively. The de-alumination behavior and the states of yielded non-framework aluminum on the treated catalysts were studied with 27Al MAS NMR. Some important properties of the treated catalysts, such as the crystalline structures, compositions, pore structures, and distribution of surface strong (S) and weak (W) acidity, Brönsted (B) and Lewis (L) acidity, have been investigated in detail with X-ray diffraction, XRF, N2 adsorption, NH3-TPD and pyridine-adsorption in situ infrared spectroscopy, respectively. The nature of strong tuning effect on the properties of the zeolite framework and surface solid acidity has been revealed for the zeolite catalyst treated with steaming, which plays the key role in tuning the S acidity and B acidity.

Key words: ZSM-5 zeolite, catalyst, binder-free, framework de-alumination, acidity