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本世纪初,一些化学家在研究铝盐水解时发现了铝离子的聚合现象。最早,Kohlschuter和Hantelman用冰点降低法测定Al∶OH=1∶1.5的水溶液,发现分子量大小相当于6个Al原子,也就是相当于Al_6(OH)_(15)~(3+),此后Brosset和Matijevec,Sillen等都提出过类似的聚合物结构。晚近用电子衍射法研究OH/Al=2—3范围内的铝盐水溶液,表明有六方晶体的衍射花样,认为它是通过OH桥基联系在一起的片状结构。近来文献中常报导的多核羟基铝化合物也是这类聚合物。制造催化剂载体γ-Al_2O_3的一种原
At the beginning of this century, some chemists discovered the polymerization of aluminum ions while studying the hydrolysis of aluminum salts. Earlier, Kohlschuter and Hantelman determined the aqueous solution of Al: OH = 1: 1.5 by freezing point reduction method and found that the molecular weight was equivalent to 6 Al atoms, which is equivalent to Al_6 (OH) _ (15) ~ (3+ Similar polymer structures have been proposed by Matijevec, Sillen et al. Recent electron diffraction studies of aqueous solutions of aluminum salts in the OH / Al range of 2-3 indicate a diffraction pattern of hexagonal crystals believed to be a sheet-like structure linked by OH bridging groups. Polynuclear aluminum hydroxy compounds, which are frequently reported in the literature, are also polymers of this type. A precursor of the catalyst support γ-Al 2 O 3 was produced