晶化时间和铝硅比对室温液相法制备A型沸石的影响

发布时间：2018-02-11 16:55

  本文关键词： 液相法 A型沸石 室温 晶化　出处：《硅酸盐学报》2017年04期 　论文类型：期刊论文

【摘要】：采用液相法室温制备A型沸石,利用X射线衍射、扫描电子显微镜、红外光谱等考察晶化时间和凝胶中n(Al_2O_3)/n(SiO_2)比对沸石的成核与晶体生长过程的影响。结果表明:晶化120 h时,反应体系以成核作用为主;120~156 h是A型沸石晶体的快速生长期;晶化时间为168 h时,合成产物具有较好结晶度。与常规95℃制备A型沸石相比,室温合成抑制了杂相的形成,延长晶化时间没有诱发羟基方钠石生成。同时,室温合成制备的样品,粒度明显减小,出现明显的附聚现象。n(Al_2O_3)/n(SiO_2)在0.35~0.80时,样品均为单相的A型沸石,提高n(Al_2O_3)/n(SiO_2)导致晶粒细化。n(Al_2O_3)/n(SiO_2)为0.35、0.45、0.60和0.80时,样品的平均粒径分别为385、329、260和192 nm。
[Abstract]:Zeolite A was prepared by liquid-phase method at room temperature. The effects of crystallization time and ratio of nnal _ 2O _ 2O _ 3 / n _ 2O _ 2O _ 2 on the nucleation and crystal growth of zeolite were investigated by X-ray diffraction, scanning electron microscopy and infrared spectroscopy. The results showed that the crystallization time was 120 h. The reaction system was characterized by nucleation at 120-156h, which was the rapid growth period of zeolite A crystal, and when the crystallization time was 168h, the synthesized product had better crystallinity. Compared with the conventional preparation of zeolite A at 95 鈩，

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