以四乙基溴化铵为模板剂气相传输法合成β沸石  

Synthesis of Zeolite Beta by the Vapour-Phase Transport Method Using Tetraethylammonium Bromide as the Organic Template

作　　者：牛田瑛[1] 李英霞[1] 李建伟[1] 陈标华[1] 

机构地区：[1]北京化工大学化工资源有效利用国家重点实验室,北京100029

出　　处：《催化学报》2009年第3期191-195,共5页

基　　金：国家自然科学基金(20676011);国家重点基础研究发展计划(973计划;2004CB217804)

摘　　要：以廉价的四乙基溴化铵为模板剂,采用原料直接混合气相传输法合成β沸石.利用X射线衍射、红外光谱和扫描电镜等手段对产物进行了表征,考察了合成条件对β沸石晶化的影响.结果表明,在硅铝比为15-200,钠硅比为0.35-0.55,模硅比大于0.12时都可以得到结晶度良好的β沸石.该方法合成β沸石需要较高的碱硅比,投料硅铝比范围宽,晶体生长速度快,423K时10h生长期已基本结束.过高的晶化温度和过长的晶化时间均易导致杂晶生成.合成的β沸石形貌随晶化时间变化,由晶化初期的椭球形转变为晶化结束时的不规则多面体.The synthesis of zeolite beta by the vapour-phase transport method using tetraethylammonium bromide （TEABr） as a cheap organic template was studied. With TEABr being solid state at room temperature, the materials were mixed directly, and the preparing xerogel was not necessary. The products were characterized using X-ray diffraction, scanning electron microscopy, and infrared spectroscopy. The crystallization process of zeolite beta was investigated. The results indicated that zeolite beta can be synthesized when the ratio of n（SiO2）/n（Al2O3） was 15-200, n（NaOH）ln（Al2O3） was 0.35-0.55, and n（TEABr）/n（SiO2） was more than 0.12. The solvent of the synthesis system was a little, which just came from vapour. The concentrations of TEA^＋ and Na^＋ were high, and the crystallization speed was fast. At 423 K, the crystallization process was completed after 10 h. The alkalinity of the system has a very important impact on the crystallization process, affecting crystallization speed and particle size. Too long time and too high temperature were disadvantageous to the crystallization of zeolite beta. The zeolite beta synthesis followed the liquid phase synthesis mechanism. At the initial crystallization stage, the morphology of the products was ellipse, and at the last crystallization stage, the products were transformed into polyhedron, The particle sizes were mostly 0.3 lam and the distribution range of sizes was narrow. The vapour-phase transport method was more promising and economical than the traditional hydrothermal method, and it can simplify the synthetic process and reduce the cost.

关 键 词：Β沸石 四乙基溴化铵 气相传输法 合成相区 模板剂 

分 类 号：O643.36[理学—物理化学]