高等学校化学学报 ›› 2015, Vol. 36 ›› Issue (4): 725-732.doi: 10.7503/cjcu20140987

• 物理化学 • 上一篇    下一篇

多级孔HZSM-5分子筛催化剂的制备及低碳烃芳构化应用

张瑞珍1,2(), 王翠1,2, 邢普1,2, 温少波1,2, 王剑1,2, 赵亮富3, 李玉平1,2   

  1. 1. 太原理工大学材料科学与工程学院
    2. 新材料界面科学与工程教育部重点实验室, 太原 030024
    3. 中国科学院山西煤炭化学研究所, 太原 030001
  • 收稿日期:2014-11-07 出版日期:2015-04-10 发布日期:2015-03-27
  • 作者简介:联系人简介: 张瑞珍, 女, 博士, 副教授, 主要从事微/介孔材料的制备、 表征及催化研究. E-mail: zhangruizhen@tyut.edu.cn
  • 基金资助:
    中国科学院战略性先导科技专项“低阶煤清洁高效梯级利用关键技术与示范”项目(批准号: XDA07020200)和山西省基础研究项目(批准号: 2012011005-7)资助

Preparation of Hierarchical Porous HZSM-5 and Its Application in Light Paraffin Aromatization

ZHANG Ruizhen1,2,*(), WANG Cui1,2, XING Pu1,2, WEN Shaobo1,2, WANG Jian1,2, ZHAO Liangfu3, LI Yuping1,2   

  1. 1. College of Materials Science and Engineering
    2. Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education,Taiyuan University of Technology, Taiyuan 030024, China
    3. Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China
  • Received:2014-11-07 Online:2015-04-10 Published:2015-03-27
  • Contact: ZHANG Ruizhen E-mail:zhangruizhen@tyut.edu.cn
  • Supported by:
    † Supported by the Strategic Priority Research Program“Demonstration of Key Technologies for Clean and Efficient Utilization of Low-rank Coal” of the Chinese Academy of Sciences(No.XDA07020200) and the Basic Research Projects of Shanxi Province, China(No.2012011005-7).

摘要:

采用0.2 mol/L的NaOH溶液对HZSM-5分子筛进行了不同时间的碱改性处理, 并对分子筛的结构和酸性进行表征, 考察了碱改性对HZSM-5催化剂的低碳烃芳构化活性的影响. 结果表明, HZSM-5分子筛经碱改性后会产生少量介孔, 且随改性时间延长, 介孔数量增加, 平均孔径增大, 总酸量降低, B酸/L酸比值降低. 120 min碱改性HZSM-5催化剂的活性、 稳定性以及目标产物苯、 甲苯、 乙苯和二甲苯(统称BTEX)的选择性最高.

关键词: 碱改性, 多级孔HZSM-5分子筛, 低碳烃芳构化, 稳定性, B酸和L酸, 选择性

Abstract:

The HZSM-5 molecular sieves were modified by 0.2 mol/L NaOH aqueous solution for 30, 120 and 300 min, respectively and the as-prepared catalysts were characterized by the X-ray diffraction, N2 adsorption-desorption, transmission electron microscopy, ammonia temperature-programmed desorption(NH3-TPD) and Fourier transform infrared spectroscopy of adsorbed pyridine. The catalytic activity, stability and BTEX selectivity of alkali-treated HZSM-5 in the light paraffin aromatization were also investigated. The results showed that the degree of crystallization decreased and the mesopores were produced in the HZSM-5 molecular sieves with the increase of alkali-treatment time, and at the same time the acidic properties of HZSM-5 could also be tuned by alkali treatment, the Brönsted acid sites were decreased while the Lewis acid sites were increased with the increase of alkali modification time. Catalytic evaluation of light paraffin aromatization over modified HZSM-5 revealed that HZSM-5 treated by NaOH for 120 min exhibited the best aromatization activity, stability and BTEX selectivity due to its suitable pore structure and acidic distribution.

Key words: Alkali treatment, Hierarchical porous HZSM-5 molecular sieve, Light paraffin aromatization, Stability, Brösted acid and Lewis acid, Selectivity

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