Optimization of crystal growth of sub-micron ZSM-5 zeolite prepared by using Al(OH)3 extracted from fly ash as an aluminum source
Optimization of crystal growth of sub-micron ZSM-5 zeolite prepared by using Al(OH)3 extracted from fly ash as an aluminum source
复制标题
以粉煤灰中提取的Al(OH)3为铝源制备亚微米ZSM-5沸石晶体生长优化
DOI：
10.1016/j.jhazmat.2018.01.004
复制
发表时间：
2018-05-05
影响因子：
13.6
通讯作者：
Zhang, Jiaojing
中科院分区：
文献类型：
--
作者：
Chen, Yanguang;Cong, Shuli;Zhang, Jiaojing
提出了一种以分阶段处理从粉煤灰中提取的Al(OH)(3)为铝源，通过水热合成法制备ZSM-5沸石的新方法。对ZSM-5的合成参数和晶体生长进行了优化。研究了有机位阻剂作用下ZSM-5晶体生长的优化。采用X射线衍射仪和扫描电镜对ZSM-5的晶相和形貌进行表征，并采用激光粒度分析仪测量其粒度分布。 ZSM-5在不同水热条件下的晶体生长均遵循“S”规律。据分析，ZSM-5晶体的形成经过四个步骤：（1）硅酸根离子与铝酸根离子缩合形成无定形铝硅酸盐； (2)非晶硅铝酸盐的颗粒生长和聚集； (3)ZSM-5的结晶及晶体生长； (4)沸石晶体达到一定尺寸后缓慢生长。有机空间位阻剂的添加导致晶粒尺寸减小并形成具有窄尺寸分布的晶体颗粒。产生单颗粒分散体，并且有机立体剂的存在改善了微孔体积、介孔体积和比表面积。 (C) 2018 Elsevier B.V. 保留所有权利。
A novel approach was proposed to prepare ZSM-5 zeolite via hydrothermal synthesis by using Al(OH)(3), which was extracted from fly ash by a staged treatment, as an aluminum source. The synthesis parameters and crystal growth of ZSM-5 were optimized. The optimization of crystal growth for ZSM-5 was investigated under the effect of organic steric-hindrance agents. The crystal phase and morphology of the ZSM-5 were characterized by X-ray diffractometry and scanning electron microscopy, and the particle size distribution was measured by laser particle-size analyzer. The crystal growth of ZSM-5 under different hydrothermal conditions obeyed the "S" regulation. According to the analysis, the formation of ZSM-5 crystal occurred via four steps: (1) the formation of amorphous aluminosilicate by the condensation of silicate ions and aluminate ions; (2) the particle growth and aggregation of the amorphous aluminosilicate; (3) crystallization and crystal growth of ZSM-5; (4) Gentle growth after the zeolite crystal reaches a certain size. The addition of organic steric hindrance agents resulted in a decrease in grain size and crystal-particle formation with a narrow size distribution. Single-grain dispersion resulted and the micropore volume, mesopore volume, and specific surface areas were improved by the presence of organic steric agents. (C) 2018 Elsevier B.V. All rights reserved.