Characterization of layered double hydroxide Mg-Al-CO3 prepared by re-hydration of Mg-Al mixed oxide

Emanation thermal analysis, differential thermal analysis, thermogravimetry, X-ray diffraction, scanning electron microscopy (SEM) and surface area and porosity determination from nitrogen adsorption/desorption measurements were used to characterize the Mg-Al-CO3 LDH compound with the Mg:Al ratio 3:1 prepared by re-hydration of the Mg-Al mixed oxide. The mixed oxide was obtained after heating of the intial Mg-Al-CO3 LDH compound in air at 500°C for 2 h. The samples were re-hydrated by two ways namely in a distilled water at 20°C for 5 days or by moistening at 60°C in air with RH 80% during 10 days, respectively. The characteristics of the re-hydrated LDH samples were compared with the initial Mg-Al-CO3 compound.