Influence of synthesis methods on structure properties of alumina. The potential of the organized mesoporous alumina with respect to use as a support

Abstract

In the present work, the synthesis methods of alumina as a support for catalytic applications have been carried out by us. We show that the synthetic way to alumina is the starting point that determines the micro- and macrostructure of the oxide and. consequently, allows control of the support characteristics. Usually, conventional aluminas with surface areas of 50 - 300 m2/g are manufactured by precipitation method. Transition aluminas (α, γ, δ, ή, θ) that were prepared by heat treatment of different aluminium oxide-hydroxide precursors (e.g. boehmite, pseudoboehmite, bayerite, nordstrandite) usually exhibit surface areas lower than 350 - 400 m2/g and their main disadvantage is in their broad pore size distribution. Recently, well-ordered mesoporous aluminas with surface areas exceeding 350  m2/g and having narrow pore size distribution were synthesized in our laboratory. This support exhibited significantly higher capacity for dispersion of active species than the conventional alumina and they have a certain potential in catalytic applications.