合成条件对SAPO-11分子筛骨架Si分布的影响

EFFECT OF SYNTHESIS CONDITION ON THE DISTRIBUTION OF Si IN THE FRAMEWORK OF SAPO-11 MOLECULAR SIEVE

在水热条件下改变合成参数合成了系列SAPO-11分子筛，采用XRD和^29Si MAS NMR等手段对样品进行表征，并考察了合成参数对SAPO-11分子筛性能的影响。结果表明，合成条件对SAPO-11分子筛的骨架Si分布有很大影响。延长晶化时间、升高晶化温度、降低硅／铝比（n（SiO2）／n（Al2O3））或控制初始溶胶pH值为5．0～5．4都可以促进骨架Si的均匀分布，得到具有较高Si分散度的SAPO-11分子筛。

A series of SAPO-11 molecular sieves were synthesized hydrothermally by varying the synthesis parameters, and were characterized by X-ray diffraction （XRD） and ^29Si MAS NMR. The effects of synthesis parameters on the properties of SAPO- 11 were also investigated. The results indicated that synthesis condition had strong influence on the distribution of Si in the framework of SAPO-11. Longer crystallization time, higher crystallization temperature, lower n （SiO2）/n （Al2O3 ） ratio and suitable pH of starting gels （c. a. 5.0-5.4） were more convenient to synthesize SAPO- 11 samples with better Si distribution.