三维有序介孔结构氧化钼制备及催化性能

Fabrication and Excellent Catalytic Performance of Three-dimensional Ordered Mesoporous Molybdenum Oxides

以三维有序介孔分子筛KIT-6为模板剂制备碳模板,七钼酸铵为钼源,采用超声辅助下的真空浸渍法,合成了三维(3D)有序介孔、蠕虫状介孔MoO3。采用TEM、HRTEM、SAED、XRD、TG/DT、N2吸脱附等对材料物理性能进行了表征。采用H2-TPR、甲苯和一氧化碳完全氧化等对催化性能进行了评价。研究发现:制备的三维有序介孔MoO3为正交相晶体结构,比表面积194 m2/g;在转化率分别为50%、90%、100%时,甲苯的起燃温度分别为203℃、215℃、225℃;CO起燃温度分别为114℃、158℃、180℃。3D-MoO3优良的催化性能与高比表面和三维有序介孔架构密切相关。

Three-dimensional （3D） ordered and wormhole-like MoO3 mesoporous structures were synthesized based on ultrasound-assisted vacuum impregnation method. Carbon template was used in the synthesis process, which was prepared by using mesoporous molecular sieve KIT-6. Hexaammonium molybdate acted as molybdenum source. The as-prepared MoO3 samples were characterized by transmission electron microscope （TEM）, X-ray diffraction （XRD）, thermogravimetric analysis/differenctial scanning calorimetry （TG/DSC）, and N2 adsorption-desorption measurement. The catalytic performance of MoO3 mesoporous structure was evaluated by hydrogen temperature-programmed reduc- tion （H2-TPR）, and complete oxidation of toluene and carbon monoxide （CO）. It was found that the initiation tem- peratures of toluene were 203℃, 215℃ and 225℃, respectively, and the initiation temperatures of CO were 114℃, 158℃ and 180℃, respectively, with their conversion rates of 50%, 90% and 100%, respectively. The well catalytic performance was attributed to 3D ordered mesoporous structure and high surface area of as-obtained MoO3 materials.