Thermal stability and characterization of ?-Al2O3 modified with lanthanum or cerium

The Role of CeO2-Doping of γ-Al_2O_3 on its Structural and Superficial Area

“…The alumina is an attractive material extensively used in chemical applications due to its high specific surface and much cleared pore structure [1,2]. However, the most catalytically active phases, such as γ-and η-Al 2 O 3 present problems at high temperatures due to phase transformations.…”

Effect of sintering atmosphere on the pore-structure stability of cerium-doped nanostructured alumina

“…It has been noted by many investigators that, in the case of transition aluminas, there is a considerable reduction in surface area during the transformation to ,,-alumina [18,24]. The rate of reduction in surface area can be retarded by suitable doping [16][17][18][19][20][21][22][23][24]. However, the actual mechanism of retardation is not clear yet [16][17][18][19][20][21][22][23][24].…”

“…One of the major difficulties in using porous nanostructured ceramics is their inherent tendency for surface area and porosity reduction. There is a large volume of literature available on the pore-structure stability of porous alumina [16][17][18][19][20][21][22][23][24][25]. It has been noted by many investigators that, in the case of transition aluminas, there is a considerable reduction in surface area during the transformation to ,,-alumina [18,24].…”

“…However, the actual mechanism of retardation is not clear yet [16][17][18][19][20][21][22][23][24]. Ba and rare earth cations are the most studied dopants and their behaviours at high temperatures vary from one another [16][17][18][19][20][21][22][23][24]. Kato et al have attributed the stability of lanthanide-doped alumina to the formation of /~-alumina type of structures [24].…”

“…The rate of reduction in surface area can be retarded by suitable doping [16][17][18][19][20][21][22][23][24]. However, the actual mechanism of retardation is not clear yet [16][17][18][19][20][21][22][23][24]. Ba and rare earth cations are the most studied dopants and their behaviours at high temperatures vary from one another [16][17][18][19][20][21][22][23][24].…”