Ammonium salt-assisted preparation of porous high-purity -Al₂O₃ with a high specific surface area

gamma-Al2O3 with a high density of active sites has been widely used. In this study, gamma-Al2O3 powder with a high specific surface area and a high purity is prepared through facile ammonium salt-assisted calcination. During the calcination process, the gases (NH3 and CO2) generated from ammonium salts can manipulate the pore and crystal structures to obtain active gamma-Al2O3 with a high purity of above 99.99 %. The results demonstrate that the specific surface areas of gamma-Al2O3 obtained by the use of ammonium carbonate (AC), ammonium bicarbonate (AB), and ammonium acetate (AA) are 441.35, 459.23, and 427.32 m2 g-1, respectively. Moreover, the gamma-Al2O3 obtained with ammonium salt shows a higher content of AlO6 than the blank group, contributing to the formation of a sponge-like morphology and more active sites. Furthermore, the active gamma-Al2O3 exhibits good performance in adsorption and desorption, making it highly valuable in various applications.