Titanosilicate ETS

Rate Nitrogen from air by PSA using carbon molecular sieve Nitrogen and methane using titanosilicate ETS-4... 

Selective photocatalysis can be achieved through the use of proper molecular sieves, such as the titanosilicate ETS-10, an alternative approach. The photocatalytic activity of ETS-10 is due to the presence of photoexcitable Ti-O-Ti chains and the three-dimensional interconnected pore system of large 12-membered ring channels in its structure, which endow the material with excellent diffusion properties [83], This regular channel system has a direct effect in determining the shape selectivity of the degradation process [84],... 

An ideal approach to achieving chiral induction in a constrained medium such as zeolite would be to make use of a chiral medium. No zeolite that can accommodate organic molecules, currently exists in a stable chiral form. Though zeolite beta and titanosilicate ETS-10 have unstable chiral polymorphs, no pure enantiomorphous forms have been isolated. Although many other zeolites can, theoretically, exist in chiral forms (e.g., ZSM-5 and ZSM-11) none has been isolated in such a state. In the absence of readily available chiral zeolites, one is left with the choice of creating an asymmetric environment within zeolites by the adsorption of chiral organic molecules. 

TITANOSILICATE ETS-10 SYNTHESIS, CHARACTERIZATION AND ADSORPTION FOR HEAVY METAL IONS... 

In conclusion, we have demonstrated the unusual adsorption behaviors of microporous titanosilicate ETS-10 towards heavy metal ions with an extremely t rate and in a large adsorption capacity, showing the application potentials of ETS-10 for water and wastewater treatment. The adsorption is most likely via ion exchange. It is believed diat die unique compositional frameworic together with the large pore size of ETS-10 play a vital role in determining its remaricable adsorption properties towards heavy metal ions. 

Lin Z, Rocha J, Navajas A, Tellez C, Coronas JQ, and Santamaria J. Synthesis and characterization of titanosilicate ETS-10 membranes. Micropor Mesopor Mater 2004 67 79-86. 

M. E. Grillo and J. Carrazza, /. Phys. Chem. B, 101, 6749 (1997). Computer Simulation Study of Aluminium Incorporation in the Microporous Titanosilicate ETS-10. 

G. X. S. Zhao, L. Jia, and P. A. Chia. Unusual adsorption properties of microporous titanosilicate ETS-10 toward heavy metal lead. Langmuir 19, 1977-1979 (2003). 

Figure 2.21 In the large-pore mixed coordination titanosilicate ETS-10, chains of corner-sharing TiOg octahedra are linked via silicate tetrahedra. The offset of the chains of octahedra between consecutive layers exhibits disorder on the long range, and end-member polytypes have not yet been prepared.

The majority of important synthetic novel zeolites, however, have not been prepared as crystals either large enough or sufficiently well ordered to be studied by available single crystal methods. Zeolites such as Beta, ZSM-12, NU-87, MCM-22 and ITQ-21, and related microporous solids such as the titanosilicate ETS-10, for example, were solved from X-ray powder diffraction and other methods (such as electron microscopy and computer simulations) rather than by single crystal diffraction. 

Structurally related titanosilicate ETS-IO," strongly supporting the layer-by-layer growth mechanism. 

Alkali metal inclusion gives rise to very strongly basic zeolites, with strong electron donating power (Lewis bases). These are very active as basic catalysts, but their reactivity is too high to permit useful application. Where reducible cations are present in the framework such as in the titanosilicate, ETS-10, inclusion of sodium metal results in the reversible reduction of the framework... 

In the examples discussed above, the transition metals are heteroatoms that occupy tetrahedral sites within the framework. There are also examples where transition metals occupy octahedral framework sites within a porous silicate framework. In the much studied titanosilicate ETS-10, in which the structure contains a mixture of octahedral titanium and tetrahedral silicon, a small fraction of the octahedral titanium may be reduced to Ti(III) by hydrogen. In addition, it is possible to include the lanthanide cerium into the mixed coordination microporous silicate AV-5. As described in Section 2.5.1, this... 

Jeon JD, Kim J, Kwak SY (2012) Nafion/microporous titanosilicate ETS-4 composite membranes for effective methanol crossover reduction in direct methanol fuel cells. J Membr Sci 415 16 353-359... 

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