纳米多级孔SAPO-11分子筛制备及其催化2-甲基萘烷基化反应  

Preparation of hierarchical nano-SAPO-11 zeolites as catalystsfor the synthesis of 2,6-dimethylnaphthalene

作　　者：张晓华[1] 张璞 纪琳[3] 江乐杰 宋艳萍[1] 魏海国[1] 曾庆峰[1] 叶闰平 冯刚 ZHANG Xiaohua;ZHANG Pu;JI Lin;JIANG Lejie;SONG Yanping;WEI Haiguo;ZENG Qingfeng;YE Runping;FENG Gang(PetroChina Planning and Engineering Institute,Beijing 100083,China;Petro China Refining,Chemicals&New Materials Company,Beijing 100007,China;Liaohe Oilfield Oil and Gas Gathering and Transportation Company,Panjin 124010,China;School of Chemistry and Chemical Engineering,Nanchang University,Nanchang 330031,China)

机构地区：[1]中国石油天然气股份有限公司规划总院,北京100083 [2]中国石油炼油化工和新材料分公司,北京100007 [3]辽河油田油气集输公司,辽宁盘锦124010 [4]南昌大学化学化工学院,江西南昌330031

出　　处：《洁净煤技术》2024年第8期162-169,共8页Clean Coal Technology

基　　金：国家自然科学基金资助项目(22362022;21875096),江西省双高资助项目。

摘　　要：SAPO-11分子筛作为微孔沸石,通常粒径大,而粒径小的SAPO-11分子筛具有较短的孔道,更有利于分子的扩散使SAPO-11分子筛具有更高的催化活性,但存在稳定性较差的缺点,如何在水热法基础上进一步合成纳米多级孔SAPO-11分子筛极具挑战。在水热合成SAPO-11分子筛基础上,通过对前驱体凝胶进行老化处理制备纳米多级孔SAPO-11分子筛。其中,在80℃用搅拌老化制备的SAPO-11分子筛有最小晶体尺寸,通过SEM可知通过搅拌老化制备的S11-80℃-stirring分子筛呈现一种均匀纳米棒状结构,这些纳米棒的直径约500~700 nm,长度约2~4μm。通过N_(2)吸附-脱附曲线及孔径分布图可知经过老化处理的SAPO-11分子筛较传统SAPO-11都具有更大的比表面积,搅拌老化与静置老化制备的分子筛相比而言具有更大的微孔比表面积与孔体积。且通过NH_(3)-TPD对SAPO-11分子筛酸性性质进行表征,所有老化处理合成的SAPO-11分子筛酸量都有所下降。2-甲基萘(2-MN)主要来源于煤焦油,可用于制备2,6-二甲基萘(2,6-DMN),用于合成高端聚酯,为此将上述纳米多级孔SAPO-11分子筛用于催化2-甲基萘烷基化反应,结果表明使用老化处理制备的纳米多级孔SAPO-11分子筛有77.8%的2-MN初始转化率,20.4%的初始选择性,2,6-DMN、2,7-DMN的物质的量比为1.13,反应第4小时有最高2,6-DMN选择性39.9%,通过系列表征揭示了纳米多级孔SAPO-11分子筛择形催化催化机理。As a microporous zeolite,SAPO-11 zeolites usually have a large particle size,and SAPO-11 with a small particle size has shorter pores,which facilitate better diffusion of molecules and thus enhance catalytic activity.However,this also leads to poorer stability.How to further synthesize hierarchical nano-SAPO-11 zeolites on the basis of hydrothermal method is a great challenge.Based on the hydrothermal method,SAPO-11 zeolites were prepared by aging treatment with the precursor gel.Among them,the SAPO-11 zeolites prepared by stirring aging treatment at 80℃has the smallest crystal size.It can be seen by SEM that the S11-80℃-stirring zeolite show a uniform nanorod-like structure,these nanorods have a diameter of about 500-700 nm and a length of about 2-4μm.The N_(2) adsorption-desorption isotherms and pore size distribution curve reveal that the SAPO-11 zeolite treated by aging has a larger specific surface area compared to conventional SAPO-11.Specifically,zeolites prepared by agitation aging show a higher specific surface area and pore volume for micropores,but lower values for mesopores compared to those prepared by static aging.The NH_(3)-TPD curves characterization of the acidic properties shows that all SAPO-11 zeolites synthesized with aging treatment have reduced acidity.2-Methylnaphthalene(2-MN),which is mainly derived from coal tar,can be used to prepare 2,6-dimethylnaphthalene(2,6-DMN),and then be used to synthesize high-end polyester.Therefore,the above-mentioned hierarchical nano-SAPO-11 zeolites were applied to catalyze the alkylation reaction of 2-methylnaphthalene.The results show that the SAPO-11 zeolites prepared by aging treatment have 77.8%initial conversion of 2-MN,20.4%initial selectivity,1.13 molar ratio of 2,6-DMN/2,7-DMN,and the highest selectivity of 2,6-DMN of 39.9%at the 4th hour of reaction.The shape selection catalytic mechanism of SAPO-11 molecular sieve was revealed by series characterization.

关 键 词：多级孔 SAPO-11 老化处理 烷基化 2 6-二甲基萘 

分 类 号：O643.36[理学—物理化学]