具有管状镶嵌结构L/EU-1复合分子筛的合成及表征

采用晶种法在极浓体系中,快速合成了L/EU-1复合分子筛,通过XRD、SEM、NH_3-TPD、TG-DTG等多种手段对其进行了表征.结果表明:随原始溶胶中添加硼和铁的质量分数的增加,复合分子筛中L分子筛的特征衍射峰分别向高角度和低角度方向发生偏移,L分子筛的晶胞参数和晶胞体积分别有所减小和增加;含硼和铁的L/EU-1复合分子筛尺寸大小长约为0.5~3μm,宽0.2~1μm,形貌为小颗粒聚集L分子筛附着生长管状镶嵌结构复合分子筛;镶嵌结构改变了复合分子筛的酸性、稳定性和孔道性质.影响因素分析表明,碱硅比低时,K~+对促进钙霞石笼的形成起主导作用,碱硅比高时,K~+对溶胶的聚沉起主导作用.

Synthesis and Characterization of L/EU-1 Composite Zeolites with the Tubular Mosaic Morphology

L/EU-1 composite zeolites were synthesized rapidly by the method of crystal seed in extremely dense system,the synthetic samples were characterized by XRD,SEM,NH3-TPD,TG-DTG and so on.The results showed that with increasing the mass fraction of boron and iron in the original sol,the characteristic diffraction peaks of L in the composite zeolites migrated to higher angle and lower angle direction,respectively.The cell parameters and cell volume of L zeolite were decreased and increased,respectively.L/EU-1 composite zeolites contains boron and iron O.5 ～ 3 μm long,width of 0.2 ～ 1 μm and they have the characteristics of small particle aggregation L zeolite attachment growth with the tubular mosaic structure.The mosaic structure changed the acidity,stability and pore properties of the composite zeolites.When n(K2O)/n(SiO2) is low,K+ plays a leading role in promoting the formation of cancrinite cages.When n(K2O)/n(SiO2) is high,K+ plays a dominating role in coaglulation of sol.