物理化学学报 >> 2009, Vol. 25 >> Issue (05): 829-834.doi: 10.3866/PKU.WHXB20090513

研究论文 上一篇    下一篇

微波辐射法合成SAPO-5分子筛中硅铝比对产物结晶度和甲苯吸附性能的影响

郝志显 赵海涛 王利军 解丽丽 田震 李庆华   

  1. 同济大学化学系, 上海 200092; 上海第二工业大学城市建设与环境工程学院, 上海 201209
  • 收稿日期:2008-11-18 修回日期:2009-01-30 发布日期:2009-05-04
  • 通讯作者: 郝志显 王利军 E-mail:haozhixian@tongji.edu.cn; ljwang@eed.sspu.cn

Effects of Si/Al Molar Ratio on the Crystallinity and Toluene Adsorption of SAPO-5 Synthesized under Microwave Radiation

HAO Zhi-Xian, ZHAO Hai-Tao, WANG Li-Jun, XIE Li-Li, TIAN Zhen, LI Qing-Hua   

  1. Department of Chemistry, Tongji University, Shanghai 200092, P. R. China; 2School of Urban Development and Environmental Engineering, Shanghai Second Polytechnic University, Shanghai 201209, P. R. China
  • Received:2008-11-18 Revised:2009-01-30 Published:2009-05-04
  • Contact: HAO Zhi-Xian WANG Li-Jun E-mail:haozhixian@tongji.edu.cn; ljwang@eed.sspu.cn

摘要:

采用硅溶胶作硅源, 用微波辐射法在酸性条件下(pH=4.5-5.0)合成了SAPO-5分子筛, 利用X射线衍射(XRD), 傅立叶变换红外光谱(FT-IR), 扫描电镜(SEM)和Brunauer-Emmett-Teller (BET)比表面积分析对样品的结晶度、形貌和比表面等进行表征, 考察了晶化原料硅铝比对分子筛结晶度和晶体颗粒长径比(c/a)的影响, 测定了分子筛对甲苯的吸附性能. 结果显示, 采用微波辐射法合成的SAPO-5分子筛, 在硅铝摩尔比为0.50附近生成产物的结晶度最好, 晶体颗粒的长径比最小(约为1.0). 尽管不同硅铝比条件下得到的样品比表面测定结果变化不大, 但对甲苯的吸附实验显示, 在硅铝比为0.50时样品的吸附速率和饱和吸附量均达到了最大值. 这与表征所得的结晶度和长径比的变化一致, 即结晶度好,长径比小的SAPO-5分子筛具有更好的甲苯吸附性能.

关键词: SAPO-5分子筛, 微波辐射法, 硅铝比, 结晶度, 长径比, 甲苯吸附

Abstract:

SAPO-5 molecular sieves were synthesized using high pressure microwave radiation and at pH=4.5-5.0. Effects of silica/alumina (Si/Al) molar ratios of the initial reaction sol-gel on the aspect ratio (c/a) of resulting crystal particles and the toluene adsorption capability of the products were investigated. X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) surface area analyses showed that good crystallinity and low crystal aspect ratio were apparent at a Si/Al molar ratio of 0.50. The highest toluene adsorption rate and quantity was obtained at around the same Si/Al molar ratio of 0.50. BET surface areas were approximately constant despite the products were obtained under the reaction conditions of different Si/Al molar ratios. The agreement obtained from the characterization and adsorption indicates that SAPO-5 molecular sieves with high crystallinity and low aspect ratio are valuable for toluene adsorption.

Key words: SAPO-5 molecular sieve, Microwave radiation, Si/Al molar ratio, Crystallinity, Aspect ratio, Toluene adsorption

MSC2000: 

  • O647