Hierarchical Aluminosilicate Synthesis and Modification

Monodispersed spherical silica (silica) was used (Superior silica, USA). Hierarchical Aluminosilicate (HAS) (SiO₂/Al₂O₃ ratio 80) with micro and meso hexagonal pores was synthesized through top-down approach using nanozeolitic seed and mesoporous template CTAB.^{34 (link)} The parent ZSM-5 (zeolyst) was dissolved in alkaline solution in presence of template and then pH adjusted using dilute sulfuric acid. The material was left for hydrothermal aging for few days and then collected through filtration, washing, drying and calcination steps. The obtained nanomaterial was further modified by refluxing using 3-aminopropyltrimethoxysilane by dispersing in toluene solution. After silane addition, the solution mixture was refluxed for 6 hours under argon atmosphere. Then solution was centrifuged, precipitated sample was washed and dried. The sample was denoted as APTMOS-HAS. For the other sample including silica, a similar refluxing procedure was carried out and denoted as APTMOS-silica.