Preparation of porous ZrO2/Al2O3 macrobeads from ion-exchange resin templates

In this work, we will report a method to prepare porous ZrO2 and ZrO2/Al2O3 macrobeads using cation-exchange resins with sulfonate groups as templates. The preparation process involves metal ion-loading, ammonia-precipitation, and calcination at an appropriate temperature. Several characterization methods, such as TGA, XRD, SEM with EDX, TEM and N-2 adsorption and desorption, were used to characterize the ZrO2 and ZrO2/Al2O3 macrobeads. The results showed that the porous structures of the resin templates were negatively duplicated in the two kinds of macrobeads. We found the following interesting results: (1) The ZrO2/Al2O3 macrobeads are composed of tetragonal zirconia nanocrystals that are more technologically important, while the pure ZrO2 macrobeads consist of a mixture of tetragonal and monoclinic zirconia. (2) In the ZrO2/Al2O3 macrobeads, the size of ZrO2 nanocrystals is about 5 nm smaller than that (about 19 nm) found in the pure ZrO2 macrobeads. (3) The ZrO2/Al2O3 macrobeads have more mesopores and, therefore, have a larger surface area than the pure ZrO2 macrobeads. These oxide macrobeads will have potential applications in catalysis by taking advantage of their macrobeads shape and pores structure.