稀土掺杂La-Al-EU-1分子筛的合成与表征  

Synthesis and Characterization of Rare Earth La-doped Al-EU-1 Zeolites

作　　者：杨冬花[1] 周志宽[1] 赵君芙[2] 葛超[1] 窦涛[3,4] 

机构地区：[1]太原理工大学化学化工学院,山西太原030024 [2]太原理工大学材料科学与工程学院,山西太原030024 [3]太原理工大学精细化工研究所,山西太原030024 [4]中国石油天然气集团公司催化重点实验室,北京102249

出　　处：《中国稀土学报》2010年第6期654-659,共6页Journal of the Chinese Society of Rare Earths

基　　金：国家重点基础发展计划(973计划;2004CB217806);国家自然科学基金项目(20973123)资助

摘　　要：在HMBr2-Na2O-Al2O3-SiO2-La2O3-H2O体系中,采用水热法合成了高结晶度的La-Al-EU-1分子筛。通过XRD,FT-IR,XPS,TG-DTG和UV-Vis DRS等手段对合成样品进行分析。结果表明：随着原始溶胶中镧的质量分数增加,La-Al-EU-1分子筛晶胞体积膨胀;FT-IR骨架振动频率向低波数方向移动,在约980 cm-1处出现Si-O-La对称伸缩振动谱带;在λ=245 nm分子筛骨架O原子的成键2p电子向骨架四配位的La原子的空d轨道的p-d跃迁产生的特征峰强度增强;La3d3/2和La3d5/2伴峰电子结合能比La2O3高1.0 eV,氧的O1s电子结合能比La2O3高1.1 eV,La3d和O1s的电子结合能同步向高能方向移动,导致La-O键共价性减少,电子云密度降低,La-O键长增加,证明了La原子已经进入了分子筛骨架,并以La3＋离子四配位方式存在;当ωLa〈0.82%,n（SiO2）/n（Al2O3）=50~80时,晶化时间24~41 h,可以合成高结晶度的La-Al-EU-1分子筛。The La-Al-EU-1 zeolites were hydrothermally synthesized in a HMBr2-Na2O-Al2O3-SiO2-La2O3-H2O system.The prepared La-Al-EU-1 zeolite samples were characterized by a series of techniques including XRD,FT-IR,XPS,TG-DTG,and UV-Vis DRS.The results showed that with the addition of La,the unit cell volume of La-Al-EU-1 zeolite inflated,and the vibration band of its framework shifted to a lower wavenumber,which resulted in a symmetric stretching band of Si-O-La that appeared at about 980 cm-1 in FT-IR spectrum.The UV-Vis DR spectrum showed that there was a characteristic peak at about 245 nm with an increased intensity for the electronic transition between O and La.The XPS results indicated that the binding energies of La 3d3/2 and 3d5/2 as well as O 1s were about 1.0 and 1.1 eV higher than that of La2O3,respectively.The increased binding energies mean that La-O reduced its covalency and electron density,but increased its bond length.All these results clearly confirmed that La ion was succesfully incorporated into the framework of Al-EU-1 zeolite with a coordination number of 4.The best conditions for preparing La-Al-EU-1 zeolites with a high crystallinity about 79.11% using a hydrothermal method were as follows： ωLa0.82% and n（SiO2）/n（Al2O3）=50~80,and the crystallization time was about 24~41 h.

关 键 词：La-Al-EU-1分子筛 掺杂 水热法 稀土 

分 类 号：TQ462.91[化学工程—制药化工] O611.4[理学—无机化学]