Preparation of mesoporous titanosilicate with isolated Ti active centers for cyclohexene oxidation

Abstract

We report the preparation of mesoporous titanosilicate with active Ti centres using CTAB as the structure directing agent and ethylenediamine as the complexing agent (TSC–ED). The final material contained isolated Ti⁴⁺ centres substituting Si⁴⁺ in the mesoporous silica framework. The crucial role played by ethylenediamine in complexing with Ti⁴⁺ during the sol–gel process and preventing the phase segregation of TiO₂ was studied systematically. The textural parameters, structural order, morphology, nature and co-ordination of Ti species were analyzed using various techniques such as X-ray diffraction (XRD), UV-vis diffused reflectance spectroscopy (UV-vis DRS), UV resonance Raman spectroscopy, Fourier transformed Infra-red spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transition electron microscopy (TEM), and X-ray photoelectron spectroscopy. Finally, the catalysts were tested for catalytic activity in the oxidation of cyclohexene using various oxidants.