硼改性HZSM-5沸石催化剂上甲苯/乙醇烷基化反应及其物化性能

THE ALKYLATION OF TOLUENE WITH ETHANOL ON HZSM-5 ZEOLITE CATALYST MODIFIED WITH BORON AND PHSICAL CHEMICAL PROPERTIES OF THE CATALYST

采用硼酸改性的HZSM-5沸石催化剂进行甲苯/乙醇烷基化反应,筛选出一种具有高的活性、选择性、同时又具有较好稳定性的催化剂。对不同硼含量的催化剂进行了几种物性表征。通过将表征数据与反应结果关联,提出了两个基本概念:催化剂上活性中心的有效利用率η和烷基化有效活性中心数δ。催化剂的改性是决定η、δ值大小的主要手段。本文对影响η和δ值大小的因素以及引入这两个概念的意义各提出了几点看法。

The alkylation of toluene with ethanol was carried out over HZSM-5 zeolite catalyst modified with boron, and a catalyst with high toluene conversion, high selectivity and good stability was selected. The acidic and structural propetries of HZSM-5 zeolite impregnated with different amount of H_3BO_3 were investigated. Two basic postulates were proposed on correlating reaction results with acidity measurements. They are: effective utilization retio of active sites on catalysts(η), and effective number of active sites for alkylation(δ). The effect of catalyst modification is interpretted in terms of η and δ.