高等学校化学学报 ›› 2022, Vol. 43 ›› Issue (8): 20220090.doi: 10.7503/cjcu20220090

• 物理化学 • 上一篇    下一篇

等级孔微孔-介孔Fe2O3/ZSM-5中空分子筛催化材料的制备及催化苄基化性能

姚伊婷1, 吕佳敏1, 余申1, 刘湛1, 李昱1, 李小云2(), 苏宝连1, 陈丽华1()   

  1. 1.武汉理工大学材料复合新技术国家重点实验室, 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
  • 收稿日期:2022-02-12 出版日期:2022-08-10 发布日期:2022-04-28
  • 通讯作者: 李小云,陈丽华 E-mail:xiaoyunli2015@whut.edu.cn;chenlihua@whut.edu.cn
  • 基金资助:
    国家自然科学基金(U20A20122)

Preparation of Hierarchical Microporous-mesoporous Fe2O3/ZSM-5 Hollow Molecular Sieve Catalytic Materials and Their Catalytic Properties for Benzylation

YAO Yiting1, LYU Jiamin1, YU Shen1, LIU Zhan1, LI Yu1, LI Xiaoyun2(), SU Baolian1, CHEN Lihua1()   

  1. 1.State Key Laboratory of Advanced Technology for Materials Synthesis and Processing
    2.State Key Laboratory of Silicate Materials for Architecture,Wuhan University of Technology,Wuhan 430070,China
    3.Laboratory of Inorganic Materials Chemistry,University of Namur,Namur B? 5000,Belgium
  • Received:2022-02-12 Online:2022-08-10 Published:2022-04-28
  • Contact: LI Xiaoyun,CHEN Lihua E-mail:xiaoyunli2015@whut.edu.cn;chenlihua@whut.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(U20A20122)

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Fe2O3/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%.

关键词: 等级孔分子筛, 碱处理, 三氧化二铁/ZSM-5, 苄基化反应

Abstract:

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 Fe2O3/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.

Key words: Hierarchically porous zeolite, Alkali treatment, Fe2O3/ZSM-5, Benzylation reaction

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