高等学校化学学报 ›› 2021, Vol. 42 ›› Issue (9): 2742.doi: 10.7503/cjcu20210070

• 无机化学 • 上一篇    下一篇

液相酸溶液后补钛合成Ti-MWW分子筛

罗强强1,2, 金少青2(), 孙洪敏2, 杨为民1,2()   

  1. 1.华东理工大学化工学院, 上海 200237
    2.中国石化上海石油化工研究院, 绿色化工与工业催化国家重点实验室, 上海 201208
  • 收稿日期:2021-01-29 出版日期:2021-09-10 发布日期:2021-09-08
  • 通讯作者: 金少青 E-mail:jinsq.sshy@sinopec.com;yangwm.sshy@sinopec.com
  • 作者简介:杨为民, 男, 博士, 正高级工程师, 主要从事分子筛催化与绿色化工研究. E-mail: yangwm.sshy@sinopec.com
  • 基金资助:
    国家重点研发计划重点专项(2017YFB0702800);国家自然科学基金(21603277)

Post-synthesis of Ti-MWW Zeolite via Titanium Incorporation in Liquid Acid Solution

LUO Qiangqiang1,2, JIN Shaoqing2(), SUN Hongmin2, YANG Weimin1,2()   

  1. 1.School of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China
    2.State Key Laboratory of Green Chemical Engineering and Industrial Catalysis,Sinopec Shanghai Research Institute of Petrochemical Technology,Shanghai 201208,China
  • Received:2021-01-29 Online:2021-09-10 Published:2021-09-08
  • Contact: JIN Shaoqing E-mail:jinsq.sshy@sinopec.com;yangwm.sshy@sinopec.com
  • Supported by:
    the National Key Research & Development Program of China(2017YFB0702800);the National Natural Science Foundation of China(21603277)

摘要:

首先在含钠体系硼酸与哌啶用量较少的条件下水热合成B-MWW分子筛前驱体, 然后对其进行液相酸溶液后补钛, 合成了高结晶度的Ti-MWW分子筛. 利用粉末X射线衍射、 氮气吸附-脱附分析、 紫外-可见漫反射光谱和紫外拉曼光谱等技术考察了硅钛比、 温度等后补钛参数对所合成Ti-MWW分子筛的织构性质、 钛物种周围配位环境及催化1-己烯环氧化性能的影响, 确定适宜液相后补钛的硅钛比为30, 温度为373 K. 并且发现, 在后补钛体系中添加少量氟化铵可显著提高所合成Ti-MWW分子筛对1-己烯环氧化的催化活性. 本研究不仅证实了酸处理Ti-MWW分子筛前驱体的脱硼补钛机制, 也为Ti-MWW分子筛的合成提供了一种新的方法与思路.

关键词: Ti-MWW分子筛, B-MWW分子筛前驱体, 酸溶液, 后补钛, 1-己烯环氧化

Abstract:

B-MWW zeolite precursor was first hydrothermally synthesized with less amount of boric acid and piperidine under the condition of sodium hydroxide introduced, and then the incorporation of titanium was performed in liquid acid solution to obtain Ti-MWW zeolite with high crystallinity. With the help of powder X-ray diffraction, N2 adsorption-desorption characterization, UV-Vis and UV Raman spectroscopies, the effects of parameters including Si/Ti ratio and temperature on the texture properties, the state of titanium species and the catalytic performance in 1-hexene epoxidation of obtained Ti-MWW zeolite were investigated. The Si/Ti ratio and temperature beneficial for titanium incorporation are 30 and 373 K, respectively. Moreover, the catalytic performance of the obtained Ti-MWW zeolite in 1-hexene epoxidation can be significantly improved with a small amount of ammonium fluoride added during post-synthesis. This study not only demonstrates the deboration-based titanium incorporation mechanism during acid treatment of Ti-MWW zeolite precursor, but also provides a new method for the synthesis of Ti-MWW zeolite.

Key words: Ti-MWW zeolite, B-MWW zeolite precursor, Acid solution, Post-incorporation of titanium, 1-Hexene epoxidation

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