化学学报 ›› 2001, Vol. 59 ›› Issue (9): 1527-1529. 上一篇    

研究论文

MFI型沸石晶体的择优定向生长

王喜庆;宋茂莹;余辉;周伟正;龙英才   

  1. 复旦大学化学系.上海(200433)
  • 发布日期:2001-09-15

Preferentially oriented growth of MFI-type zeolite crystals

Wang Xiqing;Song Maoying;Yu Hui;Zhou Weizheng;Long Yingcai   

  1. Fudan Univ, Dept Chem.Shanghai(200433)
  • Published:2001-09-15

首次采用"双模板剂"法在SiO2-Na2O-正丙胺-溴化N-乙基-六亚甲基四胺(EtHMTA^+)-NaF-H2O体系中合成得到了b轴择优取向的ZSM-5(MFI型)晶体,并用扫描电镜(SEM)和XRD进行表征。择优取向程度与所用的两种模板剂的比例有关,当正丙胺:EtHMTA^+比为0.7:0.3时,ZSM-5晶体择优取向最明显。

关键词: 定向生长, 沸石, 晶体, 二氧化硅, 氧化钠, 季胺, 氟化钠, 扫描电子显微镜, X射线衍射分析, 取向

A novel "double-template" method has been developed to hydrothermally synthesize high silica MFI-type zeolite crystal with preferentially oriented growth alog ac-plane. The reactant system for the synthesis is SiO2-Na2O-n-propylamie (n-PrNH2)-N-ethyl- hexamethylene tetrammium bromide (EtHMTA^+)-NaF-H20. SEM images show that almost all as-synthesized single crystals of the zeolite are in flat and thin form with (010) plane parallel to the test plate. The XRD patterns show that the intensity of (0k0)(k=2n) peaks is much stronger than that of any other peaks, indicating that the as- synthesized crystals are b-axis perferentially oriented on the test plate. The fraction of b-axis orientation of the crystals is strongly dependent on the ratio ofthe two templatesused in the reactant, n- PrNH2 and EtHMTA^+. The optimal molar ratio of n-PrNH2 toEtHMTA^+ IS 0. 7: 0.3 for the preferentially oriented growth of MFI-type zeolite crystals.

Key words: ORIENTED GROWTH, ZEOLITE, CRYSTALS, SILICON DIOXIDE, SODIUM OXIDE, QUATERNARY AMMONIUM COMPOUNDS, SODIUM FLUORIDE, SCANNING ELECTRON MICROSCOPES, X-RAY DIFFRACTION ANALYSIS, ORIENTATION

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