高等学校化学学报 ›› 2001, Vol. 22 ›› Issue (2): 285.

• 研究论文 • 上一篇    下一篇

沸石表面有机金属化学──ZSM-5外表面上—Ge(n-C4H9)x基团的接枝及其性质研究

王绪绪1, 赵慧霞1, 付贤智1, Frédéric LEFEBVRE2, Jean-Marie BASSET2   

  1. 1. 福州大学光催化研究所, 福州 350002;
    2. Laboratoirede Chimie Organométallique de Surface, UMRCN RS2CPE 9986, 43, Bddu 11 Novembre 1918, 69616 Villeurbanne Cedex, France
  • 收稿日期:2000-05-17 出版日期:2001-02-24 发布日期:2001-02-24
  • 通讯作者: 王绪绪(1955年出生),男,博士,副教授,从事催化和表面有机金属化学研究.E-mail:xwang@fzu.edu.cn E-mail:xwang@fzu.edu.cn
  • 基金资助:

    国家自然科学基金(批准号:29843003)资助

Surface Organometallic Chemistry on Zeolite Grafting Reaction of Ge(n-C4H9)x Fragments over ZSM-5 outer Surface and Adsorption Properties of the Resulting Materials

WANG Xu-Xu1, ZHAO Hui-Xia1, FU Xian-Zhi1, Frédéric LEFEBVRE2, Jean-Marie BASSET2   

  1. 1. Research Institute of Photocatalysis, Fuzhou University, Fuzhou 350002, China;
    2. Laboratoirede Chimie Organométallique de Surface, UMRCN RS2CPE 9986, 43, Bddu 11 Novembre 1918, 69616 Villeurbanne Cedex, France
  • Received:2000-05-17 Online:2001-02-24 Published:2001-02-24

摘要: 用气体分析及IR,NMR和元素分析等方法研究了真空系统中230和280℃下四丁基锗在ZSM-5沸石表面上的接枝反应,并对所得沸石的热稳定性和吸附性质进行了表征.与作者曾报道的在硅胶及丝光沸石上的反应类似,四丁基锗也能与ZSM-5沸石表面上的硅羟基发生缩合反应,在其外表面或孔口生成组成为(≡Si—O)xGe(nC4H9)4-x(x=13)的表面有机锗化合物.在230℃接枝丁基锗基团不影响沸石的结构和表面积,仅改变它的孔口大小.在改性后的沸石上,N2的吸附性质没有改变,而不同分子尺寸的烃,如正己烷、2甲基戊烷、2,3二甲基丁烷却呈现出完全不同于起始ZSM-5沸石的择形吸附效应.

关键词: ZSM-5, 四丁基锗, 表面修饰, 有机金属化合物

Abstract: The reaction of tetrabutylgermanium with ZSM-5 surface at 230 and 280 ℃ was studied by means of gas volumetry, infrared spectroscopy, solid-state NMRand elemental analysis. The thermal stability and the adsorption properties of the resulting solids were also determined. Acondensation occurred between tetrabutylgermanium and the surface hydroxyl groups of ZSM-5, being closly analogous to what had been observed on silica and mordenite. The products in the gas phase are C1—C4 hydrocarbons formed by cracking of the evolved butane on the highly acidic ZSM-5, and in contrast to the report on silica or mordenite, a mixture of [(≡Si—O)xGe(n-C4H9)x-4)](x=1, 2, 3) species was formed. Increasing the reaction temperature resulted in much more dealkylated species. After heating at 450 ℃, no butyl ligand remained on germanium. No modification of the solid was detected by nitrogen adsorption, showing that the zeolitic structure was retained upon grafting. The modified materials show that the adsorption properties are quite different from those of the starting ZSM-5. For example, 2,3-dimethyl butane is totally excluded from the modified zeolite while the unmodified one easily adsorbs it.n-Hexane and 2-methyl pentane are also discriminated by this zeolite but, in this case, it is due to a decrease of the sorption rate at the pore entrance due to steric hindrances caused by the grafted fragments.

Key words: ZSM-5, Tetrabutylgermanium, Surface modification, Organometallic compound

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