The correlation between aging time and pore characteristics in the synthesis of mesoporous Al2O3

Mesoporous alumina powders were synthesized by the evaporation induced self assembly (EVIS) method. Aluminum isopropoxidem, aluminum nitrate and Tri-block copolymer (pluronic P123) were used as inorganic precursors and structuring agent in this study. The prepared sols were aged under 94% relative humidity (RH) for different periods of time. The aged samples were calcined at 400 °C for 8 h. The effect of aging time on the pore characteristics was studied using Fourier transform infrared spectroscopy (FTIR), nitrogen adsorption–desorption, small and wide angle X-ray diffraction, and high resolution transmission electron microscopy. The results revealed that aging time had a significant impact on the pore size, pore volume, surface area and the degree of pore ordering in the final product. The maximum BET surface area of 307 m2/g and the corresponding pore size of about 4 nm was obtained for the sol aged for two weeks.