Modification of Aluminium Alkoxide with Different Long-Chain Chelating Agent: Hydrolysis and Characterization of the Product

Abstract

An aluminum alkoxide, [Al(OCH2CH2OCH2CH3)3] (O 1 ), was synthesized by alcohol exchange method and after characterization by 27Al NMR, 1H NMR, infrared spectroscopies and mass spectrometry was used as a precursor for the preparation of high quality γ-alumina. γ-aluminas also were prepared from [Al(OCH2CH2OCH2CH2OCH3)3] (O 2 ) and [Al(OCH2CH(CH3)CH3)3] (O 3 ) in an identical hydrolysis condition and their textural parameters compared to that of prepared from O 1 . The gels obtained from hydrolysis of aluminum alkoxides by sol–gel processing were characterized by X-ray powder diffraction, thermal analysis, scanning electron microscopy (SEM), and nitrogen adsorption–desorption analysis. The X-ray diffraction patterns showed the materials obtained from hydrolysis of O 1 , O 2 and O 3 are pseudoboehmite and converts to γ-alumina by calcinations at 800 °C. The alumina obtained from hydrolysis of O 3 showed higher surface area (SBET), slightly above 200 m2/g and lower particle size, about 40–50 nm, than aluminas prepared from the hydrolysis of O 1 and O 2 . SEM showed that morphology of alumina obtained from O 2 is different to a great extent than the ones obtained from other precursors. Moreover, a transparent monolith gel has been prepared from O 1 .