SAPO-11分子筛的微波合成与表征

Synthesis and Characterization of SAPO-11 Molecular Sieves by Microwave Radiation

采用硅溶胶作硅源,二异丙胺作模板剂,通过微波辐射法合成了SAPO-11分子筛,考察了溶胶的pH值、晶化时间、掺Si量对合成产物的影响.通过XRD,NH3-TPD,TG,BET和SEM等手段对分子筛产物的物化性质进行了系统的表征.结果表明用微波辐射法可合成得到具有AEL结构的SAPO-11分子筛,其溶胶中n（P2O5）/n（Al2O3）/n（SiO2）/n（CTAB）/n（正丁醇）/n（二异丙胺）/n（H2O）=1∶1∶（0.2～2.5）∶0.02∶10∶1.5∶30;溶胶的最佳pH值为6.5左右;晶化压力为4.7×10^5 Pa,晶化时间为180 min;当n（SiO2）/n（Al2O3）为1.9时,分子筛的酸量最大为0.43 mmol/g,且以弱酸为主.微波辐射法合成的SAPO-11分子筛颗粒更均匀、粒径更小,其粒径为3～5 μm.

SAPO- 11 molecular sieves were synthesized with silica solution as the sourcc of silica and diisopropylamine as the templates by microwave radiation. The influence of pH value, time and Si content on the products were investigated. The physicochemieal properties of the products were systematically characterized by means of XRD, NH3 - TPD, TG, BET and SEM. The results show that SAPO- 11 molecular sieves with AEL type could be synthesized through microwave radiation in the solution with the ratio of n （ P2O5 ）/n （Al2O3）/n （SiO2）/n （CTAB）/n （ n - butanol）/n （diisopropylamine）/n （H2O） is 1：1 ： （0.2-2.5） ：0.02：10 ： 1.5 ： 30, the optimum value of pH is about 6.5 ; the crystal pressure is 4.7 × 10^5 Pa and the crystal time is 180 minutes, when the value of n （SiO2）/n （Al2O3） is 1.9, the molecular sieves can get the most acid amount of 0.43 mmol/g which is mainly weak acid. The size of molecular sieve particles synthesized by microwave radiation are homogenous and smaller with the diameter size of 3 - 5 ,