分子筛结构与直链烷基苯催化合成性能的构效关系

研究了不同拓扑结构的分子筛在直链烷基苯(LAB)催化合成反应中的构效关系，对性能较优的Y型分子筛进行了孔道和酸性调变，并进行了苯和1-十二烯烷基化催化性能评价。采用X射线荧光光谱(XRF)、X射线衍射(XRD)、NH₃程序升温脱附(NH₃-TPD)、N₂低温吸附-脱附等方法对分子筛物化性质进行了表征。结果表明：酸性是影响分子筛催化活性的关键因素，中强酸酸量较高的分子筛烷基化初活性及稳定性较好；具有一维孔道结构的分子筛催化合成LAB产物中2-LAB质量分数高达83.9%，但烷基化稳定性较差；多维孔道更有利于产物扩散，烷基化稳定性较好。较小孔道尺寸的分子筛直链度和2-LAB含量较高；超笼结构不利于产物择形。Y型分子筛具有较高的中强酸酸量和十二元环多维孔道结构，烷基化活性和稳定性最优，对其进行扩孔改性、增加介孔比例，寿命可提高约33%。

Structure-Activity Relationship Between Zeolite Structure and the Catalytic Synthesis of Linear Alkylbenzene

The structure-activity relationship of zeolites with different topologies in the catalytic synthesis reaction of linear alkylbenzene (LAB) was studied, the pore structure and acidity of Y zeolites with better performance were modified, and the catalytic performance of benzene and 1-dodecene alkylation was evaluated. The physical and chemical properties of zeolites were characterized by various techniques, such as X-ray fluorescence (XRF), X-ray diffraction (XRD), NH₃ temperature programmed desorption (NH₃-TPD) and N₂ adsorption-desorption. The results indicate that acidity is the key factor affecting the catalytic activity of zeolites, and zeolites with a higher medium-strong acid content have better initial activity and stability in alkylation. The mass fraction of 2-LAB in the LAB products of zeolite with one-dimensional pore structure through catalytic synthesis reaches up to 83.9%, but the alkylation stability is poor; multi-dimensional pore structure is more conducive for product diffusion, and the alkylation stability is better. Zeolites with a smaller pore size have higher linearity and 2-LAB content; supercage structure is not conducive to shape selectivity of the products. Y zeolite with a high medium-strong acid content and 12-ring multidimensional pore structure has the optimal alkylation activity and stability, whose service life can be increased by about 33% by pore enlarging and modification after increasing the mesoporous proportion.