Titanium-containing hybrid systems

Organic-Inorganic Hybrids in Titanium-Containing Hybrid Systems... 

The isomorphous substitution of T atoms by other elements is capable of producing a novel hybrid atom molecular sieve with interesting properties a typical example is titanium-containing ZSM-5 zeolite (TS-1) [27]. Titanium-substituted MCM-41 has been synthesized in an acidic system by using either ionic surfactants (CTA+) or primary amine (DDA) as the template [46], and it has been applied as a catalyst [12]. 

The isomorphous substitution of T atoms by other elements produces novel hybrid atom molecular sieves with interesting properties. In the early 1980s, the synthesis of a zeolite material where titanium was included in the MFI framework of silicalite, that is, in the aluminum-free form of ZSM-5, was reported. The name given to the obtained material was titanium silicalite (TS-1) [27], This material was synthesized in a tetrapropylammonium hydroxide (TPAOH) system substantially free of metal cations. A material containing low levels (up to about 2.5 atom %) of titanium substituted into the tetrahedral positions of the MFI framework of silicalite was obtained [28], TS-1 has been shown to be a very good oxidation catalyst, mainly in combination with a peroxide, and is currently in commercial use. It is used in epoxidations and related reactions. TS-1, additionally an active and selective catalyst, is the first genuine Ti-containing microporous crystalline material. 

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