催化学报

催化学报 ›› 2007, Vol. 28 ›› Issue (2): 170-174.

• 研究论文 • 上一篇    下一篇

Ti-HMS和TS-1分子筛结构和催化性能的对比研究

金长子,李钢,王祥生,王云,刘海鸥   

  1. 大连理工大学精细化工国家重点实验室催化化学与工程系, 辽宁大连 116012
  • 收稿日期:2007-02-25 出版日期:2007-02-25 发布日期:2011-01-28

Comparative Study of Structure and Catalytic Properties of Ti-HMS and TS-1 Molecular Sieves

JIN Changzi, LI Gang*, WANG Xiangsheng, WANG Yun, LIU Hai’ou   

  1. Department of Catalytical Chemistry and Engineering, State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116012, Liaoning, China
  • Received:2007-02-25 Online:2007-02-25 Published:2011-01-28

PDF

765

被引次数

21

摘要： 采用长链十二烷基胺为模板剂,成功合成出含钛中孔分子筛Ti-HMS, 并针对其晶化过程、结构特征以及催化性能与修正经典法制备的微孔分子筛TS-1进行了对比. 结果表明,中孔分子筛Ti-HMS的晶化机理不同于微孔分子筛TS-1的晶化机理. 随着晶化温度的提高, Ti-HMS分子筛的相对结晶度降低,且晶化过程中母液的pH值变化不大. TEM照片显示, Ti-HMS分子筛的孔壁整体上呈无定形,在局部区域可能存在晶态或者类晶态物种. 与TS-1分子筛相比, Ti-HMS分子筛的活性中心(骨架钛)处在畸变的四面体环境中. 中孔分子筛Ti-HMS可以满足大分子硫化物(如苯并噻吩)氧化反应的要求; 对于小分子硫化物(如噻吩)的氧化反应,微孔分子筛TS-1催化剂效果更好.

关键词: 中孔分子筛, 微孔分子筛, 晶化, 噻吩, 苯并噻吩, 氧化

Abstract: The mesoporous molecular sieve Ti-HMS was synthesized using long-chain dodecylamine as the template. The crystallization process, structural properties, and catalytic performance of Ti-HMS were compared with that of microporous molecular sieve TS-1 prepared by modified classical synthesis. With the increase in crystallization temperature, the relative crystallinity of Ti-HMS decreased, and the pH value of the mother liquid changed little during the crystallization process, which might be attributed to its crystallization mechanism differed from TS-1. Unlike TS-1 having typical crystalline character, the Ti-HMS molecular sieve exhibited amorphous characteristics except for the lattice fringe in some area of its HRTEM image. The UV-Vis spectrum indicated that the framework Ti species of Ti-HMS were in distorted tetrahedral environment. In oxidation of bulky sulfur compounds such as benzothiophene, the Ti-HMS molecular sieve had very high catalytic activity, with a benzothiophene removal rate of about 100%. However, TS-1 was inactive for this reaction because of the diffusion restriction. In addition, Ti-HMS showed lower activity than TS-1 for selective oxidation of small molecular reactants owing to its weaker oxidative ability and lower shape selective catalytic performance.

Key words: mesoporous molecular sieve, microporous molecular sieve, crystallization, thiophene, benzothiophene, oxidation