“蒸汽相转化”法制备纳米晶组成的块状方钠石多级孔沸石催化材料

Synthesis of Monolith Hierarchical Sodalite Zeolite Composed of Nanocrystals by Steam-Assisted Conversion Method

将实验室合成的聚苯乙烯乳胶微球(PS)加入制备方钠石(SOD)沸石的前驱体凝胶中,在45℃条件下制得干凝胶,随后采用"蒸汽相转化"法制备了大块状SOD沸石材料。对影响多级SOD沸石形成因素进行了详细讨论。采用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、N_2吸附-脱附和压汞技术等表征手段对制备的材料进行了详细表征。结果表明通过"蒸汽相转化"法制备的大块状SOD沸石由球状多晶聚集体构成,这些球状多晶聚集体又是由粒径为50~100 nm的初级纳米晶粒组成,在初级纳米晶粒上和纳米晶粒之间形成了2~50 nm介孔结构以及由脱除PS微球形成的50~300 nm的大孔结构。

Hierarchical sodalite(SOD)zeolite was synthesized by“steam-assisted conversion(SAC)”method using the as-synthesized polystyrene(PS)microspheres as templates.The factors affecting the formation of the hierarchical SOD were discussed in details.The as-synthesized samples were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),N2 adsorption-desorption,and mercury intrusion method.The results exhibited that the as-synthesized monolithic SOD zeolite consisted of sphere-like polycrystalline aggregates which were further composed of primary SOD nano-crystals with a size of 50~100 nm.An intercrystalline and intracrystalline mesoporous structure ranging from 2 to 50 nm along with a macropore with 50~300 nm resulted from the removal of PS microspheres were created in the as-prepared SOD samples.