Effect of hydrothermal treatment on the acidity distribution of γ-Al2O3 support

The influence of hydrothermal treatment on the total acidity and the acidity distribution of γ-Al2O3 were studied in this paper. The experimental results indicated that the hydrothermal treatment of γ-Al2O3 at moderate condition (140 °C, 1.0-24.0 h) led to the formation of the plate-like γ-AlOOH crystallites with different morphologies, which resulted in the change of the surface acidity of the corresponding γ-Al2O3 supports. The increase of the reaction time in the period of 1.0-2.0 h led to the increase of the specific surface area, the surface OH, the total acidity and the ratio of the weak acidity in the acidity distribution of γ-Al2O3. The further prolongation of reaction time caused the overgrowth of γ-AlOOH crystallites, leading to the decrease of the specific surface area, the surface OH and the total acidity of the corresponding γ-Al2O3.