MODIFICATION OF ZEOLITE HZSM-5 WITH TOLUENE PRETREATMENT

Ⅰ. INTRODUCTIONPhysical treatment of the HZSM-5 catalyst with steam or coking or modification with metal salts produces high para-selectivity catalyst for alkylation or disproportionation of toluene and isomerization of xylene. However, as the para-selectivity increases, the activity always decreases, and vice versa. In this work the effect of

复合改性对分子筛性能的影响

对ZSM-5烷基选择性的研究已有较多报道,但在提高对位选择性的同时,往往导致活性的损失,产生“反向效应”,本文试图用复合改性来探讨解决这种效应的可能性 1 实验部分 氢型分子筛加粘接剂成型(Hz),于873 K下通水蒸气处理(HZ·H_2O),采用浸渍法制得P或Mg改性催化剂,改性物的含量分别为4％P_2O_5(P_1HZ)、10％P_2O_5(P_2HZ)。