Effect of Calcination Temperatures on Ratio of Atomic Weight of Al/O in Sol-Gel Method for Synthesis γ Al₂O₃ as a Buffer Catalyst

The aim of this research was to determine the effect of calcination temperatures on the ratio of atomic weight of Al/O that could affect the formation of γ-Al₂O₃ phase. The novelty of this research is how to produce γ-Al₂O₃ in single phase and nanosize by simple method (sol-gel method).The calcination process was performed at a temperature which varied of 190°C, 275°C and 320°C for 4 hours respectively and sinter process carried out at a temperature of 420°C for 6 hours. Calcination process at temperature of 320°C for 4 hours produces powder with the ratio of atomic weight of Al/O in accordance with the ratio of atomic weight of Al/O in Al₂O₃ compound, 0.6667 (2/3). This ratio is as expected for a compound according to formula of Al₂O₃. This condition also produces alumina powder with the smallest particle size on the nanometer scale of 84.5 nm. SEM test results show that the grain is still heterogenous in size and shape. The results also show that the grain is still agglomerated. (paper)