【摘要】 采用一步水热法合成了Mo-HMS催化剂,并用X射线衍射、N2吸附-脱附、透射电镜、激光拉曼光谱和紫外-可见光谱对催化剂的结构及表面钼物种进行了表征.结果表明,一步水热法可将Mo物种引入HMS载体中,而不破坏分子筛孔道结构,Mo物种在载体表面呈多种分布状态,包括单核的钼物种、聚集状态的多聚钼酸根离子(如Mo7O246)和晶相MoO3.与浸渍法制备的MoO3/HMS及溶胶-凝胶法制备的MoO3/SiO2相比,一步法可以使催化剂中MoO3晶相的含量分别下降39%和61%,在丙烯与异丙苯过氧化氢的环氧化反应中,Mo-HMS表现出最佳的催化性能.这可归结于Mo-HMS中Mo物种较高的分散度.更多还原

【Abstract】 Mo-HMS was synthesized by a one-step hydrothermal method.Its structure and surface molybdenum species were characterized by X-ray diffraction,N2 adsorption-desorption,transmission electron microscopy,laser-Raman spectroscopy,and UV-Vis spectroscopy.The results show that introducing molybdenum species into HMS does not destroy the structure of HMS zeolite.There are three molybdenum species such as the isolated molybdenum species,polymolybdate species,and little crystalline MoO3 existing in the HMS support.Compared with impregnated MoO3 /HMS and sol-gel MoO3 /SiO2,the one-step method can lead to the decrease of crystalline MoO3 content by 39% and 61%,respectively.In the epoxidation of propylene with cumene hydroperoxide,the catalytic performance of Mo-HMS is better than that of MoO3 /HMS and MoO3 /SiO2,which is due to the higher dispersion of molybdenum species in Mo-HMS.更多还原