分子筛结构与直链烷基苯催化合成性能的构效关系  

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

作　　者：刘创新 张成喜 任奎 李永祥 LIU Chuangxin;ZHANG Chengxi;REN Kui;LI Yongxiang(State Key Laboratory of Catalytic Material and Reaction Engineering,SINOPEC Research Institute of Petroleum Processing Co.,Ltd.,Beijing 100083,China)

机构地区：[1]中石化石油化工科学研究院有限公司石油化工催化材料与反应工程国家重点实验室,北京100083

出　　处：《石油学报（石油加工）》2023年第1期23-34,共12页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：国家重点研发计划项目(2017YFB0306502);国家自然科学基金项目(NSFC22108312);中国石油化工股份有限公司项目(121057)基金资助。

摘　　要：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)、NH_(3)程序升温脱附(NH_(3)-TPD)、N_(2)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%。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),NH_(3)-temperature programmed desorption(NH_(3)-TPD)and N_(2) 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.

关 键 词：分子筛 直链烷基苯 构效关系 烷基化 孔结构 酸性质 

分 类 号：TQ241.1[化学工程—有机化工]