化学液相沉积法改性ZSM-5分子筛及其催化性能

摘要/Abstract

摘要： 采用硅烷偶联剂KH540、甲基硅油以及正硅酸乙酯（TEOS）对ZSM-5分子筛进行化学液相沉积改性，通过X射线衍射、扫描电子显微镜、NH₃程序升温脱附、N₂吸附-脱附等手段对改性催化剂的晶型、形貌、酸性质和孔结构等进行表征，并以1,3,5-三异丙基苯（TIPB）的裂解作为探针反应，对改性催化剂外表面酸密度进行测定，进而将改性催化剂用于乙苯脱乙基型二甲苯异构化反应，评价其催化性能。试验结果表明：改性催化剂上的TIPB转化率下降，说明其外表面酸量减少；通过调整合适的改性条件可以使样品的乙苯转化率提高，异构化活性下降；改性剂TEOS加入的最佳质量分数为30％，此时改性催化剂上的TIPB转化率约为30％，乙苯转化率约为98％，异构化活性约为5％，二甲苯收率约为100％，苯选择性约为89％。

关键词: ZSM-5分子筛, 化学液相沉积, 异构化, 乙苯, 二甲苯

Abstract: ZSM-5 zeolitewas modified by chemical liquid deposition with silane coupling agent KH540, methyl silicone oil and tetraethyl orthosilicate (TEOS). X-ray diffraction, scanning electron microscopy, NH₃ temperature-programmed desorptionand N₂ adsorption-desorption were used to characterize the morphology, acidity and pore structure of the modified catalysts.In order to evaluate the catalytic performance, the cracking reaction of 1,3,5-triisopropylbenzene (TIPB) was used as a probe reaction to determine the acid density on the outer surface of the modified catalyst, and the modified catalyst was used for the ethylbenzene isomerization. The results showed that the TIPB conversion of the modified catalyst decreased, which indicated tha tthe acid content on the surface of the modified catalyst decreased. The conversion of ethylbenzene was increased and the isomerization activity was decreased by adjusting the modification conditions. The optimum mass fraction of TEOS was 30%, the TIPB conversion was approximately 30%,the ethylbenzene conversion, isomerization activity and xylene yield were 98%, 5% and 100%, respectively, and benzene selectivity was around 89%.

Key words: ZSM-5 zeolite, chemical liquid deposition, isomerization, ethylbenzene, xylene

刘景怡张燕挺梁亚凝宋金锐丁云龙侯楠李宁李晓峰. 化学液相沉积法改性ZSM-5分子筛及其催化性能[J]. 石油炼制与化工, 2024, 55(10): 102-108.

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