Synthesis and characterization of mesoporous alumina with high specific area via coprecipitation method

Mesoporous gamma-Al2O3 with high specific surface area is prepared via calcination of NH4Al(OH)(2)CO3 (AACH). The AACH is obtained by coprecipitation route with NH4HCO3 and NH4Al(SO4)(2) as raw materials. The effects of pH value and calcination temperature on the characterization of products are investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N-2 adsorption-desorption method and Transmission electron microscopy (TEM). The results show that mesoporous gamma-Al2O3 obtained by calcining AACH at 500 degrees C for 4 h exhibits high specific surface area of 571.32 m(2)/g, a pore volume of 0.75 cm(3)/g and pore size of 6.15 nm. With the calcining temperature increase, the specific surface area and pore volume decrease, and the pore size increase. When the calcining temperature elevates up to 900 degrees C which is higher than the application temperature of most active agents, the specific surface area of 150.67 m(2)/g, the pore volume of 0.51 cm(3)/g and pore size of 9.65 nm was obtained. (C) 2016 Elsevier Ltd. All rights reserved.