Preparation and Characterisation of Pure and Hybrid MCM-41 and MCM-48

Abstract

In the present t hesis t he synthesis and characterization of SiO 2 , Al/SiO 2 and Ti/ SiO 2 is described. MCM - 41 (Mobil composition of matter No.41) exhibiting hexagonal arrangement of mesopores in the range of 15 - 100 Å ha d been synthesi z ed using c etyltrimethylammoniumbromide (CTA B) as surfactant and tetraethyl orthosilicate (TEOS) as silica source . O ther members of this family exh ibiting cubic symmetry, had also been synthesized namely MCM - 48 (Mobil composition of matter No.48) using c etyltrimethylammoniumbromide (CTA B) as surfactant and tetraethyl orthosilicate (TEOS) as silica source and ethanol as cosolvent . Aluminium was further incorporated to get hybrid MCM - 41 mesoporous structures using alum inium isopropoxide as aluminium source , cetyltrimethylammoniumbromide (CTAB) as precursor agent and tetraethyl orthosilicate (TEOS) as silica source . The acidic st rength of the prepared catalyst was determined by Hammett indicator tests. Further, sol - gel te chnique for the preparation of Ti/ SiO 2 material was employed using titanium i sopropoxide as titanium source , silica gel as silica support and isopropanol as cosolvent . The prepared sample s had been characterized by powder X - ray diffraction (XRD) , Fourier transformed infrared ( FT - IR ) techniques and scanning electron microscopy (SEM).