物理化学学报 >> 1996, Vol. 12 >> Issue (08): 727-734.doi: 10.3866/PKU.WHXB19960811

研究论文 上一篇    下一篇

β沸石中堆垛层错结构的研究

孟宪平,王颖霞,韦承谦,张婉静,林炳雄,刘希尧   

  1. 北京大学物理化学研究所,北京 100871|北京燕山石油化工公司研究院,北京 102549
  • 收稿日期:1996-02-09 修回日期:1996-03-18 发布日期:1996-08-15
  • 通讯作者: 孟宪平

Studies on the Stacking Fault Structure in Zeolite Beta

Meng Xian-Ping,Wang Ying-Xia,Wei Cheng-Qian,Zhang Wan-Jing,Lin Bing-Xiong,Liu Xi-Yao   

  1. Institute of Physical Chemistry,Peking University,Beijing 100871|Research Institute Yanshan Petrochemical Corporation,Beijing 102549
  • Received:1996-02-09 Revised:1996-03-18 Published:1996-08-15
  • Contact: Meng Xian-Ping

摘要:

含TEA+离子的化合物作为模板剂会成的β沸石是由有序结构A、B、C到沿[001]方向堆积成堆垛层错结构.三种有序结构出现的几率分别为0.31、0.36和0.33;其数值不受样品中硅铝比的影响.几率值如此相近的原因是构成β沸石的结构单元Ⅰ的四种连接方式(见图2)能量相等.几率值之间的微小差别,是基于在晶体生长过程中支撑赶A、B和C型三维通道结构的TEA+离子以不同排列形成的难易程度不同所引起.B型对应的排列略易于C型、C型又略易于A型,因此使用此种模板剂时,A、B、C三种结构均可能出现,只能合成出具有堆垛层错结构的β沸石.由于三维通道的特点,合成β沸石对模板剂的用量必须大于具有二维通道或一维通道的分子筛合成时的用量.而且要求有机控离子不宜过大、反应温度相对较低、晶化时间相对较长,以利于有机铵高子不同取向排列的形成
.

关键词: β沸石, 结构单元, 堆垛层错, 模板剂, 四乙基铵离子

Abstract:

The framework topology of zeolite beta containing TEA+ compounds as templates is that A, B and C three ordered polytypes, pile up stacking fault structure along [001] orientation. The probability of A, B and C polytypes appeared in zeolite beta is 0.31, 0.36 and 0.33 respectively and does not change with the ratio of silica to alumina. Owing to the four connected modes of building unit I that formed framework of zeolite beta having the same energy, the above probability values come near. In the course of crystal growth the arrangement of TEA+ which sustains the three dimensional channel of the A, B and C is different. The little difference among probability values stems from the fact that the arrangement of B is easier than that of C and the arrangement of C is easier than that of A. Using this template, only zeolite beta with stacking fault structure can be synthesized. In the case, the necessary amount of template is more than that for molecular sieves with two or one dimensional channels and smaller templating molecule, lower reaction temperature and longer crystallization time are advantageous.

Key words: Zeolite beta, Building unit, Stacking fault structure, Template, TEA+