等级孔微孔-介孔Fe_(2)O_(3)/ZSM-5中空分子筛催化材料的制备及催化苄基化性能  

Preparation of Hierarchical Microporous-mesoporous Fe_(2)O_(3)/ZSM-5 Hollow Molecular Sieve Catalytic Materials and Their Catalytic Properties for Benzylation

作　　者：姚伊婷 吕佳敏 余申 刘湛 李昱[1] 李小云 苏宝连[1,3] 陈丽华 YAO Yiting;LYU Jiamin;YU Shen;LIU Zhan;LI Yu;LI Xiaoyun;SU Baolian;CHEN Lihua(State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,Wuhan 430070,China;State Key Laboratory of Silicate Materials for Architecture,Wuhan University of Technology,Wuhan 430070,China;Laboratory of Inorganic Materials Chemistry,University of Namur,Namur B-5000,Belgium)

机构地区：[1]武汉理工大学材料复合新技术国家重点实验室,武汉430070 [2]硅酸盐建筑材料国家重点实验室,武汉430070 [3]那慕尔大学无机材料化学实验室,那慕尔B-5000,比利时

出　　处：《高等学校化学学报》2022年第8期20-30,共11页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:U20A20122)资助。

摘　　要：ZSM-5分子筛具有极其均匀的孔道结构、良好的形状选择性和催化活性及耐水热稳定性,是一种高效、绿色的固体催化剂,被广泛应用于石油催化裂化、精细化工和环境保护等领域.但其单一的微孔结构大大降低了客体分子的流通扩散性,导致由大分子参与的芳烃烷基化反应受到极大限制.本文采用NaOH/四丙基氢氧化铵(TPAOH)混合碱处理微孔ZSM-5,制备了具备高结晶度、高比表面积的等级孔微孔-介孔ZSM-5中空分子筛材料,该材料在保持微孔孔道良好水热稳定性和大量活性中心的同时,还通过介孔的引入进一步促进反应物及产物的扩散,使间三甲苯苄基化反应的转化率提高了3.8倍.通过在等级孔微孔-介孔ZSM-5中空材料上负载Fe,开发出了具有双功能的等级孔微孔-介孔Fe_(2)O_(3)/ZSM-5中空催化剂,该催化剂在苯的苄基化反应中表现出优异的催化性能,当Fe负载量(质量分数)为6.67%,反应温度为75℃,反应时间为15 min时,转化率高达98.3%,选择性为81.6%,最终收率达到80.2%.As a kind of efficient and environment friendly solid catalyst,ZSM-5 zeolite shows extremely uniform pore structure,excellent shape selectivity,great catalytic activity and superb hydrothermal stability,which has already been used in plenty of fields like petroleum catalytic cracking,fine-chemicals processing and environmental protection.However,its simplex microporous structure severely reduces the diffusion of guest molecules,which results in a great limitation of aromatic alkylation reaction in which macromolecules participate.In this paper,through a method of etching ZSM-5 zeolite with NaOH/TPAOH(tetrapropylammonium hydroxide)mixed alkali,a hierarchical micro-/mesoporous ZSM-5 catalyst with high crystallinity and abundant specific surface area was prepared. This special hierarchical structure can not only maintain the great hydrothermal stability and plentiful active centers of microporous ZSM-5,but also promote the diffusion of reactants and products with the introduction of mesopores. As a result,the conversion of m-trimethylbenzene benzylation increased 3.8 times. In addition,a bifunctional hierarchical micro-/mesoporous Fe_(2)O_(3)/ZSM-5 hollow catalyst was developed by loading Fe on the hierarchical microporous- mesoporous ZSM-5 hollow catalyst mentioned above,which exhibited excellent catalytic performance in the benzylation reaction of benzene,and the conversion,selectivity and percent yield reached 98.3%,81.6% and 80.2% while Fe loading was 6.67%(mass fraction),and the reaction temperature and the reaction time were 75 ℃ and 15 min,respectively.

关 键 词：等级孔分子筛 碱处理 三氧化二铁/ZSM-5 苄基化反应 

分 类 号：O643[理学—物理化学] O611[理学—化学]