Sonochemical preparation of high surface area MgAl2O4 spinel

High surface area MgAl2O4 has been synthesised by a sonochemical method. Two kinds of precursors were used, alkoxides and nitrates/acetates and in both cases nanostructured MgAl2O4 was obtained. The effect of the addition of a surfactant during the sonication, cetyl trimethyl ammonium bromide, was also investigated. In the case of alkoxides precursors the as-made product is a mixture of hydroxides of aluminium and magnesium, while with nitrates/acetates a gel is obtained after sonication, containing the metal hydroxides and ammonium nitrate. Heating at 500 °C transforms the as-made products into MgAl2O4 spinel phase. The surface area is up to 267 m2/g after treatment at 500 °C and 138 m2/g at 800 °C.