The role of organic additives in the synthesis of mesoporous aluminas and Ni/mesoporous alumina catalysts
Résumé
Mesoporous aluminas can be prepd. using org. additives as porogens even if these are not surfactants, as is the case for glucose. It is shown here that porosity arises from glucose entrapped in the material pptd. at the beginning of the synthesis, and subsequently caramelized. After impregnation by nickel(II) salts and calcination, more difficult-to-reduce nickel aluminate is detected on mesoporous aluminas than on com. aluminas, because the surface area exposed to water is larger in the former case. The presence of citrates in the impregnating soln. helps to lower the proportion of nickel aluminate, but may also lead to larger NiO particles. [on SciFinder(R)]