Research on Structure of Al Gels with Different Basicity Using Spectroscopy Means
ZHAO Feng-hua
LIU Jing
ZHU Min
MIAO Xue-na
CHEN Mei-ting
Abstract：The X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR) and ~(27)Al magic angle apinning (MAS) nuclear magnetic resonance spectroscopy were used to investigate the structure characteristics of Al gels that were synthesized under different hasieity (R= OH/ Al). The results show that the fresh Al gels with different basicity (R=2.6, 2.7, 2.8, 2.9 and 3.0) have amorphous property. The (Al-O)_(Td) vibration band at 725 cm~(-1) of IR and charac-teristic peak of Al(O)_4 at 6.3×10~(-5) chemical shift of NMR both indicate that the Al gels has unique Keggin structure of Al_(13) species in solution. The intensity of (Al-O)_(Td) band of IR in-creases with the increasing of basicity, which indicates that the Al gel with high basicity (R= 3.0) has more Keggin structure. The decrease and disappearance of (Al-O)oh and (Al-OH_2)_(oh) IR bands at 622 cm~(-1) and 550 cm~(-1) indicate that the aggregation extent of Keggin structure of Al gel with high basicity (R=3.0) is higher. The Al gel with high basicity has better adsorp-tion performance because of more positive charge of Keggin structure.
Keywords：Al gelsXRDFTIR~(27)Al-MAS NMRKeggin structure
Publication Date：2009-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：4( 558-561 )