催化学报

催化学报 ›› 2006, Vol. 27 ›› Issue (11): 961-966.

• 研究论文 • 上一篇    下一篇

钛嫁接介孔分子筛Ti-HMS的合成、表征与催化性能

俞卫华,周春晖,倪哲明,张波,葛忠华   

  1. 浙江工业大学化学工程与材料学院; 浙江省多相催化重点实验室, 浙江杭州 310032
  • 收稿日期:2006-11-25 出版日期:2006-11-25 发布日期:2006-11-25

Synthesis, Characterization and Catalytic Performance of Titanium-Grafted Mesoporous Ti-HMS Molecular Sieve

YU Weihua, ZHOU Chunhui, NI Zheming, ZHANG Bo, GE Zhonghua   

  1. College of Chemical Engineering and Materials Science, Zhejiang University of Technology; Zhejiang Key Laboratory of Heterogeneous Catalysis, Hangzhou 310032, Zhejiang, China
  • Received:2006-11-25 Online:2006-11-25 Published:2006-11-25

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摘要： 以有机金属二氯二茂钛作为Ti源,以HMS作为载体,采用嫁接法合成了一系列不同载Ti量的Ti-HMS.HMS的模板剂通过600 ℃焙烧或乙醇萃取紧随400 ℃焙烧脱除.合成Ti-HMS用热重-差热分析、 X射线粉末衍射、 N2吸附-脱附等温线、漫反射紫外可见光谱和傅里叶变换红外光谱进行了表征,并在温和反应条件下考察了Ti-HMS对过氧化氢液相氧化对叔丁基甲苯的催化性能. 结果表明,对载体采取乙醇萃取和低温焙烧的方法脱除模板剂有利于保护嫁接反应所需要的羟基; 随着载Ti量增加,骨架Ti逐渐减少,四配位的骨架Ti在对叔丁基甲苯氧化反应中具有催化活性; 非骨架Ti导致催化活性降低.在实验条件下,对叔丁基甲苯的转化率可达9.3%, 对叔丁基苯甲醛的选择性为100%.

关键词: 钛, 嫁接, HMS分子筛, 过氧化氢, 对叔丁基甲苯, 氧化, 对叔丁基苯甲醛

Abstract: A series of Ti-HMS samples with different Ti amounts were prepared by a grafting method using organometallic titanocene dichloride as the Ti source and HMS as the support. The template of HMS was removed by calcination at 600 ℃ or by ethanol-extraction followed by calcination at 400 ℃. The Ti-HMS samples were characterized by thermogravimetric and differential thermal analysis, powder X-ray diffraction, N2 adsorption-desorption isotherm, diffuse reflectance UV-visible spectroscopy, and Fourier transform infrared spectroscopy. The catalytic performance of the Ti-HMS samples for oxidation of 4-tert-butyltoluene with aqueous H2O2 was tested under the mild conditions. Pretreatment of HMS by ethanol-extraction followed by low temperature calcination made OH groups available for grafting. The isolated framework Ti(Ⅳ) decreased with the increase in Ti loading. The four-coordinated Ti state displayed catalytic activity for oxidation of 4-tert-butyltoluene. Non-framework Ti species were responsible for low catalytic activity. A conversion of 4-tert-butyltoluene up to 9.3% and a complete selectivity for 4-tert-butylbenzaldehyde were achieved.

Key words: titanium, grafting, HMS molecular sieve, hydrogen peroxide, 4-tert-butyltoluene, oxidation, 4-tert-butylbenzaldehyle