Effect of preparation methods on properties of amorphous alumina/silicas
Effect of preparation methods on properties of amorphous alumina/silicas
复制标题
制备方法对非晶态氧化铝/二氧化硅性能的影响
DOI：
10.1039/jm9940401131
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
H. Shoji
中科院分区：
文献类型：
--
作者：
M. Toba;F. Mizukami;S. Niwa;T. Sano;K. Maeda;H. Shoji
Alumina/silicas have been prepared by three methods: complexing-agent-assisted sol–gel, coprecipitation and hydrogel kneading. The properties of these alumina/silicas were investigated by solid-state magic-angle-spinning nuclear magnetic resonance (MAS NMR), ammonia temperature-programmed desorption (TPD) and nitrogen adsorption. Al—O—Si bond formation is more effectively performed in the sol–gel alumina/silicas than in the conventional ones. This was deduced from the shift profile in the 29Si NMR spectra of the sol–gel alumina/silicas with the change in the Al/Si ratio, which is comparable to that of zeolites. Because of the effective Al—O—Si bond formation by the sol–gel method, the sol–gel alumina/silicas show much higher acid amounts than the corresponding conventional ones. As certain complexing agents can level the hydrolysis rates of silicon and aluminium alkoxides and bind both metal atoms, the use of a complexing agent is effective for the formation of Al—O—Si bonds and the preparation of alumina/silicas with high miscibility and controlled properties.
