Low-temperature synthesis of mesoporous nanocrystalline magnesium aluminate (MgAl2O4) spinel with high surface area using a novel modified sol-gel method

A simple, template-free and scalable modified sol-gel route was developed for the synthesis of mesoporous flake-like magnesium aluminate spinel (MgAl₂O₄) at low temperature (700 °C) with high surface area (281 m² g^?1). The obtained spinel materials were characterized by means of physicochemical techniques including X-ray diffraction, thermogravimetric analysis, scanning electron microscopy with energy-dispersive X-ray spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and N₂ adsorption-desorption analysis. The propylene oxide was used as gelation and pore forming agent in the sol-gel process. Different morphologies and sizes of flake were generated by the varied synthesis conditions. The result materials reveal that the textural properties of the MgAl₂O₄ product are strongly associated with the nature and amount of addictive solvent and calcination temperatures. It shows that the BET surface area decrease as the increase of calcination temperature and the optimal temperature of 700 °C result in the pure phase of MgAl₂O₄ spinel. This synthesis strategy offers a feasible approach for scalable fabrication of mixed metal oxides for various catalytic reactions or catalyst supports due to the large surface area.