含铁微孔EU-1/ZSM-5复合分子筛的合成和表征  

Synthesis and characterization of microporous EU-1/ZSM-5 composite zeolite containing iron

作　　者：杨瑞娟[1] 杨冬花[1] 武正簧[1] 冯晓娜[1] 窦涛[2,3] 吴忠华[4] 李志宏[4] 闫泽[1] 王凡[1] 汤琼[1] 

机构地区：[1]太原理工大学化学化工学院,山西太原030024 [2]太原理工大学精细化工研究所,山西太原030024 [3]中国石油大学(北京)化工学院CNPC催化重点实验室,北京102249 [4]中国科学院高能物理研究所同步辐射室,北京100039

出　　处：《燃料化学学报》2013年第5期601-606,共6页Journal of Fuel Chemistry and Technology

基　　金：国家重点基础发展规划(973计划;2012CB215002);国家自然科学基金(20973123);煤转化国家重点实验室开放基金(11-12-603)

摘　　要：采用预置晶种法合成了含铁的微孔EU-1/ZSM-5复合分子筛,并采用X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、热重-微分热重(TG-DTG)、N2吸附-脱附、紫外-可见吸收光谱(UV-vis DRS)、X射线吸收精细结构(XAFS)等手段进行了表征。结果表明,复合分子筛具有EU-1和ZSM-5的特征衍射峰,是两种晶相相互作用的分子分散晶相材料,微孔孔径较Fe-EU-1分子筛有所增大。随原始溶胶中铁的质量分数增加,复合分子筛具有的23.09°和23.94°处的特征衍射峰逐渐向低角度方向偏移;紫外-可见漫反射谱图中在220～245 nm出现了宽的吸收谱带;XAFS表征表明,1s→3d电子跃迁的弱吸收峰逐渐增强,同时在吸收边顶部出现的1s→4p吸收峰逐渐由宽变窄。合成工艺的最佳条件为,原始溶胶中铁的质量分数为0.075%～0.15%,晶种添加比例为15.0%～21.0%,晶种SiO2/Al2O3物质的量比为50～60。Microporous EU-1/ZSM-5 composite zeolites containing iron were synthesized using preset crystal seed method. The as-synthesized Fe-EU-1/ZSM-5 samples were characterized by a serious of techniques including X-ray diffraction （ XRD ）, scanning electron microscopy （ SEM ）, thermogravimetric-derivative thermogravimetric （TG-DTG）, N2 adsorption/desorption, UV-visible diffuse reflectance spectroscopy （UV-Vis DRS） and X-ray absorption fine structure （XAFS）. The results show that the composite zeolite is found consisting characteristic diffraction peaks for two kinds of zeolite structure： EU-1 and ZSM-5. The composite zeolite is a kind of molecular dispersion material with two crystal phases interaction and its micropore size is larger than Fe-EU-1 zeolite. With increasing the mass fraction of Fe in the original sol-gel, the characteristic diffraction peaks of composite zeolites in the 23.09~ and 23.94~ gradually migrate to lower angle direction. UV- vis spectrum shows that there is a broad absorption band at about 220 - 245 nm. The XAFS results show that the week pre-edge absorption peak for ls-~3d gradually strengthen, at the same time the absorption peak for l s--,＇4p in the top of absorption edge has tapper. The optimized synthesis conditions for the microporous EU-I/ZSM-5 composite zeolites containing iron are as follows： 0.075% ~0.15% of the mass fraction of Fe in the original sol- gel, 15.0% -21.0% of the mass fraction of ZSM-5 zeolite in the original sol-gel and 50 -60 of SiO2/A1203 mol ratio of ZSM-5 zeolite.

关 键 词：预置晶种 Fe—EU-1 ZSM-5 复合分子筛 合成 

分 类 号：TQ424.25[化学工程] O614.81[理学—无机化学]