A comprehensive investigation into the synthesis of the FER/MFI composite zeolite based on the isopropylamine-silica sol-NaAlO₂-H₂O system has been carried out. Parameters such as the Na₂O/SiO₂ molar ratio, SiO₂/Al₂O₃ molar ratio, water concentration, and structure-directing agent (SDA) concentration were of great importance in the crystal phase transition and the morphology control. FER/MFI composite zeolites could be successfully prepared under the conditions of the SiO₂/Al₂O₃ molar ratio ranging from 20 to 30 in the gel mixture. SEM and TEM images showed that the two different crystals (FER and MFI frameworks) in FER/MFI composite zeolites had a state of co-existence and staggered growth, which was typical of composite zeolites. Among these factors influencing the synthesis process, adjusting the Na₂O/SiO₂ molar ratio was easy to control the relative contents of each phase in the composite zeolites. The higher Na₂O/SiO₂ molar ratio was, the more content of the FER phase was. NH₃-TPD and FT-IR of adsorbed pyridine results showed the acidity properties of composite zeolites were significantly different from those of corresponding physical mixtures. Interestingly, the distribution of aluminum between the FER and MFI structures in the composite zeolites was unequal, and aluminum atoms tended to enrich in the phase predominating in the FER/MFI composite zeolites. The catalytic performance in the cracking of olefins like butene and pentene of the FER/MFI composite zeolite was superior to that of the pure ZSM-5 zeolite. The FER/MFI composite zeolite after further modification is expected to become an excellent catalyst for the catalytic cracking of low carbon olefins to ethylene and propylene.

已经对基于异丙胺-二氧化硅溶胶-NaAlO ₂ -H ₂ O体系的FER / MFI复合沸石的合成进行了全面研究。Na ₂ O / SiO ₂摩尔比，SiO ₂ / Al ₂ O ₃摩尔比，水浓度和结构定向剂（​​SDA）浓度等参数在晶体相变和形貌控制中非常重要。可以在SiO ₂ / Al ₂ O ₃条件下成功制备FER / MFI复合沸石凝胶混合物中的摩尔比为20至30。SEM和TEM图像显示FER / MFI复合沸石中的两种不同晶体（FER和MFI骨架）具有共存和交错生长的状态，这是复合沸石的典型特征。在影响合成过程的这些因素中，调节Na ₂ O / SiO ₂摩尔比易于控制复合沸石中各相的相对含量。Na ₂ O / SiO ₂摩尔比越高，FER相的含量越多。NH ₃吸附吡啶的-TPD和FT-IR结果表明，复合沸石的酸度性质与相应的物理混合物明显不同。有趣的是，复合沸石中的FER和MFI结构之间的铝分布不相等，铝原子倾向于富集在FER / MFI复合沸石中占主导的相中。FER / MFI复合沸石在烯烃（如丁烯和戊烯）裂解中的催化性能优于纯ZSM-5沸石。进一步改性后的FER / MFI复合沸石有望成为将低碳烯烃催化裂解为乙烯和丙烯的极佳催化剂。