【摘要】 分别采用溶胶-凝胶法和浸渍法制备了一系列Ni/SiO₂催化剂,将其用于催化偏三甲苯（1,2,4-TMB）的加氢脱烷基反应.结果表明,在制备过程中,无水柠檬酸（CA）的加入量对催化剂的结构、表面性质、粒径及催化性能均有较大影响.催化剂表面L酸位上1,2,4-TMB几乎不发生歧化和异构化反应.镍硅体系催化剂上主要副反应为苯环加氢,通过调整还原镍的粒径可有效控制苯环加氢,从而提高了二甲苯（BTX）的选择性.在最佳反应条件下,10Ni/Si-2.0催化剂上1,2,4-TMB的转化率最高为29.4%,BTX的选择性为99.9%.更多还原

【Abstract】 A series of Ni/SiO₂ catalysts,prepared via sol-gel and impregnation methods,respectively,was tested in the reaction of hydrodealkylation of 1,2,4-trimethylbenzene（1,2,4-TMB）. The results showed that the volume of citric acid anhydrous（CA） have great influence on the structure,surface properties,particle size and catalytic properties. 1,2,4-TMB hardly reacted disproportionation and isomerization reaction on Lewis acid sites. The hydrogenation of benzene ring was main adverse reaction on Ni/SiO₂ catalysts. The particle size of Ni on the catalyst could be adjusted in a certain range by changing the amount of CA,and the resultant catalysts exhibited high selectivity for Benzene-Toluene-Xylene（BTX）. With the optimum reaction conditions,the highest conversion of 1,2,4-Trimethylbenzene was 29. 4% and the selectivity of BTX was 99. 9% on the10 Ni/Si-2. 0 catalyst.更多还原