硅钛改性ZSM-5分子筛抑制“反向效应”的探讨

The “Opposit-effect” Restraining Performance of Zeolite ZSM-5 Modified by SiCl_4 and TiCl_4

本文采用 SiCl_4和 TiCl_4对 ZSM-5分子筛进行改性,考察硅和钛的氯化物改性对分子筛的调变作用,关联甲苯乙醇乙基化反应与表面酸性及孔结构的变化。阐明了能够兼顾调整酸强度和保持孔结构畅通性的改性方法,有助于克服 ZSM-5分子筛改性过程中“反向效应”的现象.从实验结果看,ZSM-5分子筛经水蒸汽老化处理后,以 TiCl_4进行改性,能制出对甲苯乙基化具有较高初活性和对位选择性的催化剂.

The catalytic,surface acid and channel structure properties of high temperature steam-treated ZSM-5 zeolite,modified by SICl_4 and TiCl_4, were examined systematically with NH_3-TPD,XRD,FTIR and toluene ethylation with ethanol.The modified method which could enhance the content of middle-strength acid sites and remain the channel diffusing cfreely is favorable to restrain or overcome the“opposite-effect”.