Abstract Layered double hydroxides with the composition M2+/Al3+ (M2+ = Zn, Mn, Mg or Co) and M2+:Al3+ molar ratios of 2:1, intercalated with NH4+/SO42− were investigated. After optimizations steps varying the pH of precipitation and observing the X-ray diffraction patterns and Fourier-transform infrared spectra, the phases were synthesized by co-precipitation at increasing pH and characterized by several instrumental techniques. The basal distance of all optimized compounds was close to 11 A, but after the ripening process at 90 °C, ammonium was only maintained in the materials containing Zn and Co, presenting the chemical composition (NH4)[M2+6Al3(OH)18(SO4)2] while the materials containing Mn and Mg presented the chemical composition close to M2+4Al2(OH)12(SO4)1.0. Investigations to exchange topotactically NH4+ with Na+ and Na+ with NH4+ in Zn2+/Al3+ samples indicated that these reactions are partially reversible, with a partial reduction of the intercalated sulfate anions content.

中文翻译：

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新型层状双氢氧化物插层铵/硫酸盐的合成和拓扑交换反应

摘要 研究了具有 M2+/Al3+ 组成（M2+ = Zn、Mn、Mg 或 Co）且 M2+:Al3+ 摩尔比为 2:1 且插入 NH4+/SO42- 的层状双氢氧化物。经过优化步骤改变沉淀的 pH 值并观察 X 射线衍射图和傅里叶变换红外光谱，在增加的 pH 值下通过共沉淀合成相，并通过几种仪器技术进行表征。所有优化化合物的基础距离接近 11 A，但在 90 °C 的熟化过程后，铵仅保留在含有 Zn 和 Co 的材料中，呈现化学成分 (NH4)[M2+6Al3(OH)18 (SO4)2] 而含有 Mn 和 Mg 的材料的化学成分接近 M2+4Al2(OH)12(SO4)1.0。