Studies on the improved thermal stability for doped ordered mesoporous γ-alumina.

Ordered mesoporous γ-alumina (OMA), Ce-doped, Zr-doped and Ce-Zr-codoped OMA samples were synthesized in a sol-gel system with P123 as the soft template, both salicylic acid and citric acid as the assistant templates. The results show that the incorporations of either cerium or zirconium or both are able to improve the thermal stability of OMA. The capability to preserve the structural ordering and suppress the phase transition from γ-Al2O3 to α-Al2O3 at high temperature observed on the doped OMA is due to the formation of CeO2, ZrO2 or Ce(x)Zr(1-x)O2 phase, which is capable of protecting OMA from the structural collapse by sintering and phase transition.