核壳型SAPO-34/AlPO-18分子筛的制备及生长机理  

Synthesis and Growth Mechanism of the Core-Shell SAPO-34/AlPO-18 Molecular Sieves

作　　者：张琳[1] 田鹏[1] 苏雄[1,2] 樊栋[1,2] 王德花[1,2] 刘中民[1] 

机构地区：[1]中国科学院大连化学物理研究所洁净能源国家实验室(筹),甲醇制烯烃国家工程实验室,辽宁大连116023 [2]中国科学院研究生院,北京100049

出　　处：《催化学报》2012年第10期1724-1729,共6页

基　　金：中国博士后科学基金(2011M500583)~~

摘　　要：采用水热法制备了核壳型SAPO-34/AlPO-18分子筛,并运用X射线衍射、扫描电镜和超高分辨场发射扫描电镜等方法对样品进行了表征.结果表明,通过改变实验条件可有效调控壳层AlPO-18纳米晶在SAPO-34晶体表面的生长,从而得到具有不同生长区域、生长取向及紧密度的核壳型SAPO-34/AlPO-18分子筛.超高分辨场发射扫描电镜结果发现,核相SAPO-34晶体的外表面结构与壳层AlPO-18纳米晶的生长性质紧密相关,从而推测出核相晶体外表面微细结构诱导壳层分子筛生长的晶化机理.The core-shell molecular sieves comprised of SAPO-34 as core and AlPO-18 as shell were hydrothermally synthesized and characterized by X-ray diffraction,scanning electron microscopy（SEM）,and ultra-high resolution field-emission scanning electron microscopy（FE-SEM） techniques.The SEM results show that the growth of the shell AlPO-18 nanocrystals with different orientations and compactness can be controlled by adjustment of the synthesis conditions such as core pretreatment,liquid to solid ratio,and growth number.The ultra-high resolution FE-SEM images confirm that the growth performance of the shell AlPO-18 is closely related to the surface microstructure of SAPO-34,indicating the mechanism that the microstructure on the external surface of the core directs the growth of the shell.

关 键 词：核壳分子筛 SAPO-34 AlPO-18 生长机理 超高分辨场发射扫描电镜 

分 类 号：O643.36[理学—物理化学]