TS-1 and Related Materials A Materialized Dream

One of the most important industrial achievements in the field of liquid-phase selective oxidation has been the discovery of titanium silicalite-1 (TS-1) at Eni in the late 1970s, by Taramasso and co-workers. Thanks to the unique reactivity properties of TS-1, several innovative processes that use hydrogen peroxide are now industrial processes, and others are under advanced development. 

about 30 years after TS-1 discovery, industrial catalysts are well developed and present in the technology portfolio of Polimeri Europa (since 2012, Versalis), a petrochemical company wholly owned and controlled by Eni S.p. A. It is important to underline the key role of the most innovative proprietary catalysts, which have been developed as fundamental elements , of some of the most advanced technologies. 

A complete description of the peculiarities of TS-1 material and catalysts based upon it is not the objective of this chapter. An abundance of high-quality papers concerning TS-1 are available, as are papers on related materials, syntheses, characterizations and applications. However, a few words are needed. Incorporation of titanium, in a tetrahedral coordination, into high-silica molecular sieve frameworks is the basis of the exceptional catal3hic properties of the material. By using a mental model, if an all-silica MFl framework (mordenite framework inverted, eg. silicalite-1, S-1) is the host of atomically dispersed titanium, we are in the presence of a TS-1 material. 

TS-1 is obtained by hydrothermal synthesis, from the progressive condensation of Si04 and Ti04 tetrahedra around the template ion (i-C3H7)4N+ (from tetrapropy-lammonium hydroxide). 

The crucial problem in the synthesis procedure is to find the proper conditions to obtain an isolated, tetrahedrally coordinated titanium species, since titanium greatly prefers an octahedral coordination. 

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