摘要：

Layered double hydroxides (LDH) containing Mg II, Fe III, and Al III in the brucite-like layers and interlayer carbonate (with a constant M II/M III ratio but varying Al III/Fe III ratios) have been prepared and characterised by X-ray diffraction, thermal analysis, FT-IR and UV-VIS/diffuse reflectance spectroscopies, temperature-programmed reduction and specific surface area assessment through low temperature adsorption of N 2. An Mg,Al-LDH, but with intercalated hexacyanoferrate(III), has been also prepared and characterised, in which simultaneous formation of the carbonate analogue did not occur. Thermal decomposition in air at 450 and 750°C leads to MgO and poorly crystallised MgFe 2O 4 spinel (crystallinity increasing with the iron content), while for the hexacyano-containing sample, crystallization only is observed after calcination at 900°C. This different behaviour has been related to the initial location of the iron ions.

展开