Synthesis and characterization of Al_(13)-oxalate gel with Keggin structure  

作　　者：LIU Jing ZHAO Fenghua 

机构地区：[1]The Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology, Mianyang 621010, China [2]he Key State Laboratory of Coal Resource ＆ Mining Safety, China University of Mining and Technology, Beijing 100083, China [3]Department of Resource and Earth Science, China University of Mining and Technology, Beijing 100083, China

出　　处：《Chinese Journal Of Geochemistry》2009年第4期364-368,共5页中国地球化学学报

基　　金：supported by the specialized re-search fund for the Doctoral Program of Higher Edu-cation of China (Grant No 2006029009);the Program for New Century Excellent Talents in China University of Mining and Technology (Grant No NCET-07-0801)

摘　　要：In this study, the Al13-oxalate gel synthesized from Al13 solution was characterized by XRD, FTIR and MAS 27Al NMR. The results are: 1) the gel shows obvious XRD diffraction peaks, which is different from common Al gels and their oxalate precipitations; 2) the peak of Al-O stretch vibration of Al13-oxalate complexes at 810 cm-1 indicates that the gel was formed directly by the complexes, and the characteristic peaks of IR and solid-state NMR respectively occur at 725 cm-1 and ～6.1×10-5 chemical shift, which are respectively assigned to (Al-O)Td vibration and (Al-O)4 tetrahedron, suggesting that the gel has a unique Keggin structure; 3) Al13 polyoxocation can directly form gel with oxalate, even in a high-pH environment (=7.8). This finding provides new evidence for the universality of Al13 in natural environments. Through chemical analysis, the chemical formula of the gel was determined to be AlO4Al12(OH)24(H2O)12(C2O4)7/2.In this study, the Al13-oxalate gel synthesized from Al13 solution was characterized by XRD, PTIR and MAS 27A1 NMR. The results are： 1） the gel shows obvious XRD diffraction peaks, which is different from common AI gels and their oxalate precipitations; 2） the peak of A1-O stretch vibration of Al13-Oxalate complexes at 810 cm^-1 indicates that the gel was formed directly by the complexes, and the characteristic peaks of IR and solid-state NMR respectively occur at 725 cm^-1 and -6.1×10^-5 chemical shift, which are respectively assigned to （AI-O）Td vibration and （A1-O）4 tetrahedron, suggesting that the gel has a unique Keggin structure; 3） Al13 polyoxocation can directly form gel with oxalate, even in a high-pH environment （=7.8）. This finding provides new evidence for the universality of Al13 in natural environments. Through chemical analysis, the chemical formula of the gel was determined to be AlO4Al12（OH）24（H2O）12（C2O4）7/2,

关 键 词：KEGGIN结构 AL13形态 智能凝胶 草酸沉淀 合成 固体核磁共振 表征 伸缩振动 

分 类 号：O641.4[理学—物理化学] TU991.22[理学—化学]