表面钝化型二维ZSM-5分子筛的制备及甲苯与甲醇烷基化性能  

Preparation of surface passivated 2D ZSM-5 zeolites and their performance in toluene and methanol alkylation

作　　者：曾浩桀 周媚 邹镇远 熊峰 曾星星 刘宝玉 ZENG Haojie;ZHOU Mei;ZOU Zhenyuan;XIONG Feng;ZENG Xingxing;LIU Baoyu(School of Chemical Engineering and Light Industry,Guangdong University of Technology,Guangzhou 510006,Guangdong,China;Guangdong Provincial Laboratory of Chemistry and Fine Chemical Engineering Jieyang Center,Jieyang 515200,Guangdong,China)

机构地区：[1]广东工业大学轻工化工学院,广东广州510006 [2]化学与精细化工广东省实验室揭阳分中心(广东省榕江实验室),广东揭阳515200

出　　处：《化工进展》2024年第5期2696-2704,共9页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金(21978055,22278090);广东省省级科技计划(2022A0505050073)。

摘　　要：采用二次晶化技术在二维ZSM-5分子筛表面构筑了具有外表面钝化作用的全硅Silicalite-1结构,通过XRD、SEM、TEM、N_(2)吸附-脱附等温线、Py-IR等手段对所制备的催化剂进行表征,采用固定床反应器评价了表面钝化型二维ZSM-5分子筛在甲苯和甲醇烷基化反应中的催化性能。表征结果表明:二次晶化技术在保留ZSM-5分子筛内部二维片层结构的同时成功构筑了全硅Silicalite-1钝化表面,Silicalite-1钝化结构不仅能有效屏蔽二维ZSM-5分子筛外表面Brønsted酸位点,抑制二甲苯异构化副反应的发生,而且对PX(对二甲苯)具有择形扩散的性能,极大提高对二甲苯选择性。实验结果显示:表面钝化型二维ZSM-5分子筛在673K、WHSV=10h^(-1)的条件下表现出了较长的寿命,同时在反应40h后依然有较高的活性,且对二甲苯选择性达到了约35%,在甲苯与甲醇烷基化反应中表现出优异的催化性能,有效促进了甲苯与甲苯烷基化高选择性地制备对二甲苯的工业化应用进程。The external surface of 2D(two-dimensional)ZSM-5 zeolite was passivated by fabricating full silica Silicalite-1 through secondary crystallization technique.The obtained catalysts were characterized by XRD,SEM,TEM,N_(2) adsorption-desorption isotherms,and Py-IR,etc.The catalytic performances of the surface passivated two-dimensional ZSM-5 zeolite in the alkylation between toluene and methanol were evaluated in a fixed-bed reactor.The characterization results showed that the full silica Silicalite-1 passivated 2D ZSM-5 zeolites with internal 2D lamellar structure were successfully constructed,and the Silicalite-1 not only effectively shielded the Brønsted acid sites on the external surface of 2D ZSM-5 zeolite and inhibited the occurrence of xylene isomerization,but also possessed the ability of shape-selectivity towards PX(p-xylene),which greatly improved the selectivity of p-xylene.The surface passivated 2D ZSM-5 zeolite also showed a long lifetime at 673K,and WHSV=10h^(-1),and maintained high activity after 40h,with the selectivity of p-xylene about 35%,indicating an excellent catalytic performance in the alkylation of toluene with methanol.The present research could accelerate the industrialization procedure of alkylation between toluene and methanol.

关 键 词：ZSM-5 纳米结构 对二甲苯 分子筛 多相反应 

分 类 号：O643[理学—物理化学]