B,A1-ZSM-5沸石的制备及其在烷基化反应中的应用

Synthesis of B, Al-ZSM-5 zeolite and its application to alkylation reaction

将改性物质硼酸在沸石合成中引入，制得了 Ｂ，ＡＩ—ＺＳＭ—５沸石，简化了改性过程。经 Ｘ射线衍射谱证明：合成的 Ｂ，ＡＩ—ＺＳＭ—５沸石具有典型的 ＺＳＭ—５沸石结构特征。由沸石的晶胞参数和晶胞体积明显减少；以及ＩＲ骨架振动谱图表明硼已进入沸石骨架，并随硼含量的增加，使催化剂的总酸量逐渐下降，增加了 Ｌ酸中心的含量，强 Ｌ酸中心增多。在 Ｂ，ＡＩ—ＺＳＭ—５沸石催化剂上的甲苯－乙醇烷基化反应，使对乙基甲苯的选择性明显地增加，对乙基甲苯含量占总乙基甲苯量的８２％左右。

Modification acid as a modification agent is introduced during the synthesis of zeolite, and B,Al-ZSM-5 zeolite is formed thereafter. The said modification process is simplified. The XRD pattern of B,Al-ZSM-5 zeolite shows that it has typical character of the structure of ZSM-5 zeolite, but has lower crystallinity. Due to the distinct decrease of cell parameters and cell dimension and the IR frequency shift, it shows that the boron atoms have entered the skeleton of the said zeolite. The total acid quantity decreases with the increase of boron content, but the relative amount of Lewis acid sites and the strong Lewis acid sites increases yet. Para-methylethylbenzene selectivity of the tolyol-ethynol alkylation reaction on B,Al-ZSM-5 zeolite catalyst increases obviously. The PMEB concentration in the product reaches about 82%.