Preparation, Characterization, And Application Of Three-Dimensional Ordered Macroporous (3DOM) Materials

In recent years, three-dimensionally ordered macroporous（3DOM） materials withuniform pore size and well-defined periodic structure have been a hot research topic due totheir potential applications, such as photonic crystals, catalysts, catalytic supports,chromatographic packing materials, chemical sensors and adsorbents. Colloidal crystaltemplating methods have been a very promising method to fabricate3DOM materials.In this study, monodisperse polystyrene （PS） spheres were prepared by emulsifier-freepolymerization technology. Through changing the quantity of initiator, the diameter ofobtained PS spheres was360nm,440nm,500nm,737nm, respectively. The preparedspheres were assembly to colloidal crystal templates via a evaporation self-assembly method.several three-dimensionally ordered macroporous （3DOM） CeO₂having hierarchical porestructure were successfully prepared via a dual ’hard-soft’ templating strategy usingCe（NO₃）₃·6H₂O containing phenol-formaldehyde （PF） resol or/and sucrose as the ceriaprecursor. The resulting CeO₂samples were characterized by N2adsorption-desorptionanalysis, scanning electron microscopy, transmission electron microscopy and X-raydiffraction, which showed that the hierarchical3DOM CeO₂possessed interconnectednetworks of the ordered macropore structures with large mesopores, and both the BET surfacearea and pore volume increased significantly compared with the conventional3DOM CeO₂.The improved textural parameters should be attributed to the emergence of mesopores in theinterconnected three-dimensional skeleton, which were formed by oxidative removal ofcarbon produced from carbonization of PF resol or sucrose. The hierarchical3DOM CeO₂exhibited a superior performance to the conventional3DOM or bulk CeO₂when used assupports for Ir catalysts in preferential CO oxidation.And then, a series of3DOM Al₂O₃-C nanocomposite possessing a homogeneouscomposition of aluminum and carbon on a molecular level were successfully prepared via adual ’hard-soft’ templating strategy using C9H21AlO3containing phenol-formaldehyde （PF）resol as the aluminum precursor. The resulting samples were characterized by N2adsorption-desorption analysis, scanning electron microscopy, transmission electronmicroscopy and X-ray diffraction. The resulting alumina-carbon nanocomposites exhibithighly ordered3D macroporous structures.In contrast to previously reported Alumina-carbonhybrid materials （ACHMs）, the walls of the present3DOM Al₂O₃-C nanocomposite arecomposed of homogenously distributed alumina and carbon. Moreover, the new nanocomposite is an excellent support for Pt catalysts, which exhibit high catalytic activitiesfor toluene （Tol） hydrogenation.