盖媛媛,贾志奇,赵丽丽,赵永祥.热处理过程中SiO2-Al2O3酸性质演变及催化四氢呋喃聚合性能[J].分子催化编辑部,2013,(2):166-172
热处理过程中SiO2-Al2O3酸性质演变及催化四氢呋喃聚合性能
Evolution of Acidity Properties and Catalytic Performance for Tetrahydrofuran Polymerization of SiO2-Al2O3 during Heat Treatment Process
投稿时间:2012-12-04  修订日期:2013-03-21
DOI:
中文关键词:  SiO2-Al2O3  热处理  酸性质  织构性质  THF聚合
英文关键词:SiO2-Al2O3  heat treatment  acidity  texture  THF polymerization
基金项目:国家自然科学基金项目(面上项目,重点项目,重大项目)
作者单位E-mail
盖媛媛 山西大学化学化工学院 gyyswh@yahoo.com.cn 
贾志奇 山西大学 jiazq@sxu.edu.cn 
赵丽丽 山西大学 lzhao@sxu.edu.cn 
赵永祥 1.山西大学化学化工学院2.精细化学品教育部工程研究中心 yxzhao@sxu.edu.cn 
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中文摘要:
      采用溶胶-凝胶法制备Al2O3含量为30 wt.%的SiO2-Al2O3复合氧化物,借助热重-差热分析 (TG-DTA)、N2物理吸附、X射线粉末衍射 (XRD)、傅里叶变换红外 (FTIR)、氨程序升温脱附 (NH3-TPD) 和吡啶吸附红外 (Py-IR) 光谱研究了500 ~ 900 ℃范围的热处理过程对SiO2-Al2O3结构、织构、酸性质的影响规律,并与四氢呋喃 (THF) 聚合性能进行关联。结果表明,经500 ℃热处理的SiO2-Al2O3拥有高的比表面积、大量的Si–O–Al键以及丰富的酸性中心。随着热处理温度升至700 ℃,SiO2-Al2O3的织构性质无显著变化,Si–O–Al键数量减少,SiO2-Al2O3总酸量和酸密度下降,强酸中心消失。至900 ℃时,比表面积和孔体积急剧下降,平均孔径显著增加,酸量和酸密度进一步减少。聚合反应结果表明,产品的收率和分子量均随热处理温度的升高呈现上升趋势。900 ℃时,产品收率最高,可达47 %,聚合物分子量 (Mn) 为1710。
英文摘要:
      SiO2-Al2O3 with 30 wt. % Al2O3 content has been synthesized via sol-gel procedures. The evolution of their surface properties during the heat treatment process from 500 ~ 900 ℃ has been characterized by Thermal gravity-Differential thermal analysis (TG-DTA), N2 adsorption, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, FTIR spectroscopy of adsorbed Pyridine (Py-IR), and temperature programmed desorption of NH3 (NH3-TPD). The catalytic performances were examined for the polymerization of tetrahydrofuran (THF). The experimental results indicated that high specific surface area, numerous Si–O–Al bonds and abundant acid sites were obtained at 500 ℃. As the temperature of heat treatment increased to 700 ℃, the textural parameters of SiO2-Al2O3 did not exhibit obvious change, while the amount of Si–O–Al bonds, total acid sites and acid density decreased. The strong acid sites became absent at this temperature. At 900 ℃, the specific surface area and pore volume decreased sharply and the pore size increased significantly. The amount of Si–O–Al bonds, total acid sites and acid density further decreased. The evaluation results showed that the yield and molecular weight (Mn) of the polytetrahydrofuran (PTHF) increased as the temperature increased. At 900 ℃, SiO2-Al2O3 displayed the highest acidity (47 %) and the largest Mn (1710).
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