高等学校化学学报 ›› 2004, Vol. 25 ›› Issue (8): 1490.

• 研究论文 • 上一篇    下一篇

丝光沸石水蒸气/酸浸渍脱铝的多核固体核磁共振研究

张铭金1,2, 陈雷2, 易德莲1, 郑安民2, 杨俊2, 邓风2, 岳勇2, 叶朝辉2   

  1. 1. 武汉科技大学化学系, 武汉430081;
    2. 中国科学院武汉物理与数学研究所, 波谱与原子分子物理国家重点实验室, 武汉430071
  • 收稿日期:2003-09-10 出版日期:2004-08-24 发布日期:2004-08-24
  • 基金资助:

    国家重大基础研究前期研究专项(批准号:2002C=CC02200);国家自然科学基金(批准号:20273082);波谱与原子分子物理国家重点实验室基金资助

A Multinuclear Solid State NMR Study on Dealumination of Mordenite by Steaming and Acid-leaching

ZHANG Ming-Jin1,2, CHEN Lei2, YI De-Lian1, ZHENG An-Min2, YANG Jun2, DENG-Feng2, YUE Yong2, YE Chao-Hui2   

  1. 1. Department of Chemistry, Wuhan University of Science and Technology, Wuhan 430081, China;
    2. State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
  • Received:2003-09-10 Online:2004-08-24 Published:2004-08-24

摘要: 采用1H,29Si,27Al魔角旋转固体核磁共振(MASNMR)及1H-29Si交叉极化(CP)技术研究丝光沸石水蒸气/酸浸渍脱铝过程中各种铝物质的结构与性质.结果表明,丝光沸石上骨架铝原子在水分子作用下,生成非骨架四配位铝物质[Al(OH)3(H2O)],分别在27Al谱δ45和1H谱δ3.0处出现共振信号,这种铝物质不同于扭曲四配位铝,在高温下进一步水合生成Al(OH)3(H2O)2和Al(OH)3(H2O)3,即非骨架五配位和六配位铝物质.1H-29SiCP和1H谱证实,水蒸气脱铝使丝光沸石产生了大量的硅羟基和铝羟基.

关键词: 1H, 29Si, 27AlMASNMR, 1H-29SiCP, 水蒸气/酸浸渍脱铝, 非骨架四配位铝, 脱铝机制

Abstract: The steamed and acid-leached mordenite samples were examined by high-resolution solid state 1H, 29Si, 27Al magic angle spinning (MAS) and 1H/ 29Si cross polarization (CP) NMR spectroscopic techniques in order to study the aluminum species and evaluate the dealumination process during steaming and leaching. The NMR experiments provide a direct evidence for the existence of nonframework four-coordinated Al species,Al(OH)3·H2O,giving rise to a 1H resonance at δ 3.0 and a 27Al shoulder peak at δ 45,which are different from the distorted four-coordinated Al species. At a high temperature,water molecules will favor the formation of these Al species and extra-framework penta- and hexa-coordinated Al species in the 27Al spectrum at δ 30 and δ 0,respectively. 1H/ 29Si CP and 1H MAS NMR showed the presence of an abundance of SiOH and AlOH groups in the dealuminated mordenites during the steaming process.

Key words: 1H,29Si, 27Al MAS NMR, 1H/ 29Si CP, Steaming/acid-leaching dealumination, Nonframework four-coordinated Al, Dealumination mechanism

中图分类号: 

TrendMD: