A novel template-free sol–gel synthesis of silica materials with mesoporous structures and zeolitic walls
Hierarchical porous materials with zeolite structures show great promise in catalysis due to combining the advantages of zeolites and mesoporous materials. Here a novel template-free sol–gel method is developed to synthesize hierarchical porous silica materials. This method involves solvothermal recrystallization of the xerogel converted from uniform silicalite-1 precursor sol via vacuum drying process. The zeolite sol and the solid samples were characterized by laser light scattering, XRD, N2 adsorption/desorption isotherm, FTIR, SEM, TEM and thermal analysis technologies. The results show that we obtain two novel materials with different mesoporous structures and silicalite-1 walls by using different recrystallization media, one of which has irregular arrays of mesopores, the other possesses 3D wormhole mesoporous structure. We speculate that formation of different mesoporous structures results from different nucleation and growth process of materials
KeywordsMesoporous materials Zeolites Sol–gel method Template-free
The authors gratefully acknowledge financial supports from the SINOPEC (Grant No. X503008) and the National Nature Science Foundation of China (Grant No. 20321303). We sincerely thank Senior Engineer Shishan Sheng and Associate Prof. Wenling Chu for N2 adsorption/desorption isotherms measurement.
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