Structural and textural characteristics of systems based on layered Mg-Al hydroxides

摘要: Hydrotalcite-type layered Mg-Al hydroxides with Mg/Al ≥ 2 and related oxide systems have been synthesized characterized. During the synthesis of = 3, interplanar spacings decrease because replacement interlayer NO 3 − anion by CO 2− anion. Morphologically, initial materials are aggregates ∼1-μm oblong planar particles a structure. The transverse dimension plates is 50–100 nm, their thickness 10–30 nm. As rule, these heavily distorted. Heat treatment in temperature range from 450 to 600°C causes separation structures into domains epitaxial MgAl2O4/MgO structures, which survive heat at 900°C. this 900°C, greater part sample breaks down two-dimensional defective MgO MgAl2O4 phases whose size up 100 compositions large pore volume fairly high specific surface area, retained upon 1000–1100°C.