High purity mesoporous Γ-AL2O3 from kano kaolin in the presence of polyethylene glycol 6000 (PEG-6000) surfactant

Abstract

Mesoporous γ-Al2O3 with large surface area and narrow pore size was synthesized from acid-leachates of calcined kaolin in the presence of polyethylene glycol 6000 (PEG-6000) surfactant at room temperature. The synthesized alumina was characterized by X-ray diffraction (XRD), Nitrogen adsorption-desorption, Fourier transform infra-red spectroscopy (FTIR), field emission scanning electron microscopy (FESEM) with energy-dispersive X-ray analysis (EDX), and thermogravimetric-Derivative thermal analysis (TG-DTA). High-purity mesoporous γ-Al2O3with large surface area of 365.1 m2/g, narrow pore size distribution centred at 5.3 nm and pore volume of 0.46 cm3/g was obtained at 500 °C. When the calcination temperature has increased to 700 °C, the surface area decreased to 272.9 m2/g. Crystallite size calculated using Scherer’s equation revealed the average size of 4.33 and 4.12 nm for alumina calcined at 500 and 700 °C, respectively. The excellent pore structural properties (high surface area and large pore volume) of the synthesized mesoporous γ-alumina in the present study will allow for higher loading of active catalytic phases, as such it can be used as catalyst support.