The sol-gel route in synthesis of Cr(III)-containing clays. Comparison between Mg-Cr and Ni-Cr anionic clays

摘要: Mg/Cr and Ni/Cr hydrotalcites (HTs) were synthesised by the sol-gel method. This route was for first time explored Cr(III)-containing HTs. The hydrotalcite starting with magnesium ethoxyde nickel acetylacetonate, respectively, as divalent cation precursors chromium acetylacetonate trivalent precursor using basic catalysis (sodium hydroxide). Pure containing materials M(II)/Cr(III) = 3 obtained. presence of Ni(II) favoured increasing crystallinity. samples investigated X-ray diffraction spectroscopic techniques, DTA/TGA measurements transmission electron microscopy (TEM). obtained compounds pure phases very similar structural features, but exhibited particularities depending on M(II) cation. nanosized in both cases. IR spectroscopy evidenced that retained some organic groups surface, thus decomposition processes sample being different from Mg(II) one. process ended at lower temperature case hydrotalcite.