高等学校化学学报

高等学校化学学报 ›› 2009, Vol. 30 ›› Issue (5): 959.

• 研究论文 • 上一篇    下一篇

核壳型复合分子筛ZSM-5/Nano-β的合成与表征

童伟益1, 刘志成2, 孔德金2, 祁晓岚2, 郭杨龙1   

    1. 结构可控先进功能材料及其制备教育部重点实验室, 华东理工大学工业催化研究所, 上海 200237;
    2. 中国石油化工股份有限公司上海石油化工研究院, 上海 201208
  • 收稿日期:2008-09-11 出版日期:2009-05-10 发布日期:2009-05-10
  • 通讯作者: 孔德金, 男, 博士, 教授级高级工程师, 主要从事石油化工催化剂及工艺研究, E-mail: djkong@sript.com.cn; 郭杨龙, 男, 博士, 教授, 主要从事催化新材料与新技术研究, E-mail: ylguo@ecust.edu.cn
  • 基金资助:

    国家“九七三”计划(批准号： 2009CB623501)资助.

Synthesis and Characterization of ZSM-5/Nano-β Core-Shell Composite-Zeolites

TONG Wei-Yi1, LIU Zhi-Cheng2, KONG De-Jin2*, QI Xiao-Lan2, GUO Yang-Long1*   

    1. Lab for Advanced Materials, Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai 200237, China;
    2. Shanghai Research Institute of Petrochemical Technology, China Petroleum & Chemical Lorporation(SINOPEC), Shanghai 201208, China
  • Received:2008-09-11 Online:2009-05-10 Published:2009-05-10
  • Contact: KONG De-Jin, E-mail: djkong@sript.com.cn; GUO Yang-Long, E-mail: ylguo@ecust.edu.cn

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摘要：

以ZSM-5小晶粒为核相材料, 用聚二烯丙基二甲基氯化铵(PDDA)进行表面预处理后, 黏附nano-β晶种并焙烧制得核相晶种, 再在壳层晶化生长体系中通过水热合成得到ZSM-5/nano-β有序的核壳分子筛. 产物的物相和结构通过XRD, SEM, TEM以及N2吸附/脱附分析表征, 通过对比发现, β壳层的合成以白炭黑为硅源比用正硅酸乙酯(TEOS)更好. 通过NH3-TPD表征, 以及1,3,5-三甲苯裂化转化反应对分子筛的性能进行了考察, 结果表明, 核壳分子筛通过调变组成分子筛的酸性, 从而大大提高了材料的催化裂化性能, 同时延缓了失活速率.

关键词: ZSM-5分子筛, 纳米β分子筛, 核壳复合分子筛, 阳离子聚电解质, 硅源

Abstract:

ZSM-5/nano-β core-shell composite-zeolites were hydrothermally synthesized by a secondary growth on core ZSM-5 with a uniform size of 1 μm, which was pre-adsorbed with nano-β seeds after pretreated with positive PDDA(poly dimethyldiallylammonium chloride), and then was calcined in air. The obtained products were characterized by XRD, SEM/TEM, and N2 sorption analysis, which demonstrated the formation of ordered core-shell structure. The results proved the formation of composite-zeolites with a ZSM-5 core(ca.82%) and a poly-nano-β shell(ca.18%). The coverage of shell was tested via Sexternal measurements of the products, and the core ZSM-5 showed a more compact shell with fumed silica rather than TEOS as the silica source. Moreover, tested by NH3-TPD and probe reactions on 1,3,5-TMB cracking, it is found that the surface acidity changed after the growth of nano-β layer, and the formed ZSM-5/nano-β has a better catalytic performance(ca.80% conversion) and lower deactivation rate.

Key words: ZSM-5 zeolite, Nano-β zeolite, Core-shell, Cationic polyelectrolyte, Silica source

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