Synthesis of high surface area Al2O3-CeO2 composite nanopowder via inverse co-precipitation method

In the present work, Al2O3-CeO2 composite nanopowder was synthesized by inverse co-precipitation method using metal chlorides, aluminum powder and NH4OH as precipitant agent. The thermal decomposition of the precipitate and subsequent formation of Al2O3-CeO2 were investigated by X-ray diffractometery, scanning electron microscopy, thermogravimetric and differential thermal analysis, Brunauer-Emmett-Teller surface area measurement and Fourier transform infrared spectroscopy. The results showed that the presence of ceria suppressed the formation of α-Al2O3. The BET-specific surface area was 173 m2/g for powders calcined at 800 °C. The particle size examined by using scanning electron microscopy was in the range 30-70 nm. The activation energy of Al2O3-15 wt.% CeO2 nanocrystallite growth during calcination was measured to be 32.4 kJ/mol whereas that of Al2O3 was about 23.8 kJ/mol.