Effect of peptization of pseudoboehmite by nitric acid on the porosity and mechanical properties of γ-Al2O3

Samples of γ-Al 2 O 3 were prepared by peptization of pseudoboehmite with different amounts of HNO 3 with subsequent plasticization and extrusion, drying, and annealing to 823 K. It was found that the basic aluminum salts obtained in peptization decompose during annealing, forming a new phase which plays the role of a binder between the individual secondary aggregates and penetrates macropores. The mechanical strength of the samples of g-Al 2 O 3 increases with an increase in the amount of HNO 3 , and the volume of macropores decreases significantly and the mesopore radius increases slightly