丝光沸石水蒸气/酸浸渍脱铝的多核固体核磁共振研究  

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

作　　者：张铭金[1] 陈雷[2] 易德莲[1] 郑安民[2] 杨俊[2] 邓风[2] 岳勇[2] 叶朝辉[2] 

机构地区：[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

出　　处：《高等学校化学学报》2004年第8期1490-1494,M005,共6页Chemical Journal of Chinese Universities

基　　金：国家重大基础研究前期研究专项 (批准号 :2 0 0 2 CCC0 2 2 0 0 );国家自然科学基金 (批准号 :2 0 2 73 0 82);波谱与原子分子物理国家重点实验室基金资助

摘　　要：采用 1 H,2 9Si,2 7Al魔角旋转固体核磁共振 ( MAS NMR)及 1 H-2 9Si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( H2 O) ],分别在 2 7Al谱 δ45和 1 H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( H2 O) 2 和 Al( OH) 3( H2 O) 3,即非骨架五配位和六配位铝物质 .1 H-2 9Si CP和1 H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 .The steamed and acid-leached mordenite samples were examined by high-resolution solid state 1H, 29 Si, 27 Al magic angle spinning (MAS) and 1H/ 29 Si 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\5H 2O,giving rise to a 1H resonance at δ 3.0 and a 27 Al 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 27 Al spectrum at δ 30 and δ 0,respectively. 1H/ 29 Si CP and 1H MAS NMR showed the presence of an abundance of SiOH and AlOH groups in the dealuminated mordenites during the steaming process.

关 键 词：^1H ^29Si ^27Al MAS NMR ^1H-^29Si CP 水蒸气/酸浸渍脱铝 非骨架四配位铝 脱铝机制 

分 类 号：O647[理学—物理化学] O482.53[理学—化学]