金属掺杂介孔分子筛MCM-41的合成及结构表征

Synthesis and Characterization of Mesoporous Molecular Sieve MCM-41 with Metal Doping

采用水热法合成了不同金属原子(M=Ce,Y,Nd)掺杂的MCM-41介孔分子筛M-MCM-41,采用X射线衍射(XRD)、N2吸附-脱附、透射电镜(TEM)、X射线光电子能谱(XPS)和NH3程序升温脱附(NH3-TPD)对M-MCM-41介孔分子筛的介孔结构,金属化合价态及表面酸性进行表征。结果表明,M-MCM-41介孔分子筛仍具有典型的六方介孔结构特征,样品比表面积、孔容积降低,孔径增大,引入分子筛中金属元素以M3+形态存在,金属离子的掺杂使M-MCM-41产生酸性位,对应中强酸。

M -MCM -41 mesoporous molecular sieve with different metal doping（ M = Ce, Y, Nd） was synthesized by hydrothermal method. The surface acidity, mesoporous structure, and chemical state of metal were characterized by means of X-ray diffraction （XRD）, NH3 temperature programmed desorption （ NH3-TPD ）, transmission electron microscopy （ TEM ）, X-ray photoelectron spectroscopy （XPS） and N2 adsorption-desorption. The results indicate that M- MCM- 41 mesoporous molecular sieve exhibited the typical hexagonal mesoporous structure, and that the specific surface area and pore volume decreased with average pore diameter increasing. The metal element introduced into the molecular sieve was M^3＋ valence state. The M - MCM -41 produced acid with metal doping, corresponding to medium strong acid.