微波辅助高效水热合成SAPO-11分子筛

Microwave-assisted hydrothermal synthesis of SAPO-11 molecular sieves

采用微波辅助的方法,以拟薄水铝石、硅溶胶等为原料,合成出纯相SAPO-11分子筛,大大减少了晶化时间,节约了合成成本。通过X射线衍射(XRD),扫描电子显微镜(SEM)对合成的样品进行表征,详细考察了硅源、模板剂、硅铝比及晶化条件(晶化时间、晶化温度、pH)对合成的影响。结果表明,pH及晶化时间的影响较为显著,以硅溶胶为硅源,以二正丙胺为模板剂,在n(SiO2)∶n(Al2O3)=0.6、pH=5.7、晶化温度为185℃、晶化时间为10 h的条件下,采用微波辅助可以高效地合成纯相的SAPO-11分子筛。

The pure SAPO-11 molecular sieves were synthesized by microwave-assisted method and with pseudo-boehmite and silica gel etc. as raw materials.The method greatly reduced the crystallization time and saved the cost of synthesis.The prepared samples were characterized by powder X-ray diffraction and scanning electron microscopy.The influences of silica source ,structure-directing agent ,the ratio of silica to alumina and the crystallization conditions （such as time ,temperature, and pH） on the synthesis of pure SAPO-11 have been investigated in detail.The results indicated that the influences of pH and crystallization time were significant.The pure phase SAPO-11 molecular sieves were efficiently synthesized via mi- crowave-assisted method using silica gel as silicon source, and di-n-propylamine as template agent under the conditions of crystallization temperature of 185 ℃ ,crystallization time of 10 h ,pH=5.7 ,and n（SiO2）：n（Al2O3）=0.6.