A new way to control the coordination of titanium (IV) in the sol-gel synthesis of broom fibers-like mesoporous alkyl silicaatitania catalyst through addition of water

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2013-04, Vol.222, p.23-31
• Main Authors: Nizar, Umar, Efendi, Jon, Yuliati, Leny, Gustiono, Dwi, Nur, Hadi
• Format: Article
• Language: English
• Subjects: Catalysts; Fourier transforms; Polymerization; Scanning electron microscopy; Sol gel process; Spectrometers; Transmission electron microscopy; X-rays
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2013.02.053

In this research, the tetrahedral and octahedral coordination of Ti(IV) in alkyl silicaatitania has been successfully controlled by the addition of water in sol-gel process. Octadecyltrichlorosilane (OTS) and tetraethyl orthotitanate (TEOT) were used as precursors. The effect of the addition of water on the local coordination of Ti(IV) was analyzed by using Fourier transform infrared (FTIR) spectrometer, diffuse reflectance ultra-violet visible (DR UV-Vis) spectrometer, field emission scanning electron microscope (FESEM), X-ray diffraction (XRD) spectrometer and transmission electron microscope (TEM). It was demonstrated that water facilitate the formation of SiOTi bond which is related to the tetrahedral Ti(IV). These materials exhibit the pattern of peak at the small angle of X-ray diffractogram and type IV shape adsorption-desorption isotherms characteristic of mesoporous silicaatitania. The mesoporous structure shaped like abroom fibersa, arranged by lamellar structure like fibers with diameter size about 3a5 nm has been clearly observed by TEM. The catalytic activity of alkyl silicaatitania catalysts obtained was tested in polymerization of styrene in the presence of aqueous hydrogen peroxide. It showed that the presence of the tetrahedral Ti(IV) gave a beneficial effect in increasing the activity in this catalytic reaction.