高等学校化学学报

高等学校化学学报 ›› 1996, Vol. 17 ›› Issue (6): 944.

• 论文 • 上一篇    下一篇

不同镧含量LaNaY沸石的129Xe NMR研究

魏忠1, 王兴隆1, 李全芝1, 薛志元2, 毛学文3, 唐荣荣3, 邵敬豪3, 原所良3   

  1. 1. 复旦大学化学系, 上海 200433;
    2. 复旦大学分析测试中心, 上海 200433;
    3. 中国石油化学工业总公司兰州炼油化工总厂
  • 收稿日期:1995-06-07 出版日期:1996-06-24 发布日期:1996-06-24
  • 通讯作者: 李全芝
  • 作者简介:魏忠,男,27岁,硕士.
  • 基金资助:

    国家自然科学基金;中国石油化工总公司兰州炼油化工总厂资助

129Xe NMR Studies on LaNaY Zeolites with Various Lanthanum Contents

WEI Zhong1, WANG Xing-Long1, LI Quan-Zhi1, XUE Zhi-Yuan2, MAO Xue-Wen3, TANG Rong-Rong3, SHAO Jing-Hao3, YUAN Suo-Liang3   

  1. 1. Department of Chemistry, Fudan University, Shanghai 200433;
    2. Analytical and Measuring Centre, Fudan University, Shanghai 200433;
    3. Lanzhou Petroleum Processing and Chemical Complex, Lanzhou
  • Received:1995-06-07 Online:1996-06-24 Published:1996-06-24

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摘要： 用129XeNMR技术研究了LaNaY沸石在不同镧含量时的离子定位情况,发现经350℃抽真空预处理后,即使在低镧含量时也有部分镧离子留在超笼内,其数目取决于沸石中总的镧含量。当平均每单胞内镧离子数达到8个后,在350℃下方钠石笼中出现镧离子对,不可逆地形成桥式镧氧(氢氧)化物;但低于此含量时,镧离子处于不同方钠石笼中,而不成对发生反应。通常认为Na+离子与Xe的化学位移无关,但129XeNMR测试结果表明;在超笼中不定位的Na+可与Xe作用并影响其化学位移,而其它Na+则无此作用。

关键词: 129XeNMR, LaNaY沸石, 离子定位

Abstract: The location of cations in LaNaYzeolites with various lanthanum contents(from 1.5 to 18.7 La ions/u.c.) has been studied by 129Xe NMR technique.It is found that all LaNaY samples pretreated at 350℃ in vacuum,even with low lanthanum content,have some lanthanum cations remaining in supercages,and the amount of cations in supercages depends on the total content of lanthanum in zeolites,When the lanthanum content exceeds 8La ions/u.c.,couples of lanthanum cations appear in sodalites(β cages),and irreversibly form bridging lanthanum oxide or oxyhydroxide species at temperature 350℃,but below this content,the reaction doesn't occur,and lanthanum cations located in different sodalites,respectively,Usually,Na129 cations in Yzeolite as a whole are considered as being independent of the chemical shift of Xe atoms,but according to our result of 129Xe NMR,the unlocated Na129cations in supercage have an interaction with Xe and affect the chemical shift of xenon.

Key words: 129Xe NMR, LaNaY Zeolite, Cation Location

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