表面活性剂AEO⁃3对β沸石合成的促进作用

Promotion Effect of Surfactant AEO⁃3 on Synthesis ofβZeolites

在常规β沸石的水热合成体系中加入非离子型表面活性剂脂肪醇聚氧乙烯醚(AEO-3),按照nAl2O3∶nSiO2∶nNa2O∶nTEAOH∶nH2O∶nAEO-3∶nC2H5OH=(0.28~1)∶40∶1.55∶10∶640∶(0.45~7.69)∶11.37的配料比,考察其作为助剂对β沸石合成的影响。实验发现,与常规合成体系相比,AEO-3的加入可促进硅铝酸盐溶胶的生成并增加了其均匀化程度,同时增加了产品收率。所合成样品的X射线衍射、N2和Ar吸附-脱附、扫描电镜、固体核磁和正癸烷吸附的表征结果表明,表面活性剂AEO-3的加入使β沸石的纳米晶粒更加完整与均匀,提高了结晶度和微孔体积,并使得收率提高。所合成的β沸石的骨架硅铝比提高,酸强度增加。另外,AEO-3的加入提高了β沸石结构中的手性多形体A的比例。

The effect of the nonionic surfactant primary alcobol ethoxylate(AEO-3)as an additive on the crystallization ofβzeolites was investigated by adding it into the conventional hydrothermal synthesis system of theβzeolites with a formula of nAl2O3∶nSiO2∶nNa2O∶nTEAOH∶nH2O∶nAEO-3∶nC2H5OH=(0.28~1)∶40∶1.55∶10∶640∶(0.45~7.69)∶11.37.It was indicated that the addition of AEO-3 could promote the formation of aluminosilicate sol and increase the degree of its homogenization,as well as the yield of the product.The as-synthesized samples were characterized by X-ray diffraction,N2 and Ar adsorption-desorption,scanning electron microscope,NMR and n-decane adsorption.The results showed that the nano particles ofβzeolites were more complete and uniform,the crystallinity and micropore volume increased by the addition of surfactant AEO-3,and the yield of product,Si/Al ratio and acid strength increased as well.In addition,the addition of AEO-3 increased the proportion of chiral polymorph A in the structure ofβzeolites.