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化学学报
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化学学报 ›› 1999, Vol. 57 ›› Issue (4): 377-382. 上一篇    下一篇

研究论文

CXN天然沸石的研究1: 离子交换与结构性质表征

邱瑾;张国强;姜慧文;龙英才;孙尧俊   

  1. 复旦大学化学系.上海(200433);复旦大学分析测试中心.上海(200433)
  • 发布日期:1999-04-15

Studies on CXN natural zeolite 1: Ion exchange and structural characterization

Qiu Jin;Zhang Guoqiang;Jiang Huiwen;Long Yingcai;Sun Yaojun   

  1. Fudan Univ, Dept Chem.Shanghai(200433);Fudan Univ, Ctr Anal & Measurement.Shanghai(200433)
  • Published:1999-04-15

PDF

385

被引次数

23

采用离子交换和焙烧等方法,对我国CXN天然沸石(STI型)进行改性。应用化学分析,粉末XRD,TG/DTA,^2^7AlMASNMR,^2^9SiMASNMR,低温N~2吸附等方法表征相关的结构、离子交换等性质。CXN沸石的晶胞组成Na~0~.~2Mg~0~.~1Ca~8~.~4[Al~1~7~.~2Si~5~4~.~8O~1~4~4].65H~2O,属富钙型。经离子交换脱Ca^2^+后的沸石在焙烧过程中伴随有骨架脱铝,骨架的热稳定性已由原样的500℃以下提高到700℃以上。交换改性后的沸石,呈现反映该沸石微孔特性的I型氮吸附等温线。

关键词: 沸石, 离子交换, 热稳定性, Ｘ射线衍射分析, 热重量分析, 氮, 吸附

CXN zeolite, a natural STI type zeolite in China, was modified by ion exchange and calcination. The structural properties of raw zeolite and modified zeolite were characterized by chemical analysis, powder XRD, TG/DTA, ^2^7Al MAS NMR, ^2^9Si MAS NMR and nitrogen adsorption. The raw zeolite is rich in calcinium with cell composition of Na~0~.~2Mg~0~.~1Ca~8~.~4[Al~1~7~.~2Si~5~4~.~8O~1~4~4]. 65H~2O. After treatment of ion-exchange and de-calcinium, the zeolite was found to be de-alunminumated in the framework during calcination. Therefore the thermal stability of the modified zeolite was increased from 500℃ for raw material to 700℃. The type I adsorption isotherm of nitrogen proved the nature of the micropore in the zeolite.

Key words: ZEOLITE, ION EXCHANGING, THERMAL STABILITY, X-RAY DIFFRACTION ANALYSIS, THERMOGRAVIMETRY, NITROGEN, ADSORPTION

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