A facile seed-assisted strategy was employed to synthesize ZSM-5 zeolites with different Al distribution through varying the Al content in the ZSM-5 seed and the synthetic gel, respectively. One ZSM-5 zeolite (Z1) displays Al-rich rim, synthesized by epitaxial growth on pure silica crystal seed in the Al-containing gel. The other ZSM-5 sample (Z2) has Al-homogeneous distribution obtained from Al-containing seed and pure silica gel. The both samples were determined by desilication process, XPS and 2,6-DMP adsorption IR analysis etc. Sample Z1 and Z2 perform almost the same initial conversion in n-hexane cracking reaction, but Z2 possesses the higher stability and higher olefin yield than Z1 with time on stream. There is low deactivation rate on the Z2, due to its Al-homogeneous distribution favorable for retaining channel connectivity and enhanced diffusivity, while more external coke deposit on Z1 occurs, having serious pore blocking due to its Al-rich rim.

通过改变ZSM-5种子和合成凝胶中的Al含量，采用一种简便的种子辅助策略来合成具有不同Al分布的ZSM-5沸石。一种ZSM-5沸石（Z1）具有富铝边缘，该边缘是通过在含铝凝胶中的纯二氧化硅晶体种子上外延生长而合成的。另一个ZSM-5样品（Z2）具有从含Al种子和纯硅胶获得的Al均匀分布。两种样品均通过脱硅工艺，XPS和2,6-DMP吸附红外分析等方法测定。样品Z1和Z2在正己烷裂化反应中的转化率几乎相同，但Z2具有比Z1更高的稳定性和更高的烯烃收率随着时间流逝。Z2的停用率很低，