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A titanosilicate molecular sieve with adjustable pores for size-selective adsorption of molecules

Nature volume 412, pages 720–724 (2001)Cite this article

An Erratum to this article was published on 11 October 2001

Abstract

Zeolites and related crystalline microporous oxides—tetrahedrally coordinated atoms covalently linked into a porous framework—are of interest for applications ranging from catalysis to adsorption and ion-exchange1. In some of these materials (such as zeolite rho) adsorbates2, ion-exchange, and dehydration and cation relocation3,4 can induce strong framework deformations. Similar framework flexibility has to date not been seen in mixed octahedral/tetrahedral microporous framework materials, a newer and rapidly expanding class of molecular sieves5,6,7,8,9,10,11,12,13,14,15,16. Here we show that the framework of the titanium silicate ETS-4, the first member of this class of materials8, can be systematically contracted through dehydration at elevated temperatures to ‘tune’ the effective size of the pores giving access to the interior of the crystal. We show that this so-called ‘molecular gate’ effect can be used to tailor the adsorption properties of the materials to give size-selective adsorbents17 suitable for commercially important separations of gas mixtures of molecules with similar size in the 4.0 to 3.0 Å range, such as that of N2/CH4, Ar/O2 and N2/O2.

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Figure 1: ETS-4 framework.
Figure 2: ETS-4 dehydration and associated decrease of the lattice constants.
Figure 3: Reduction in the eight-membered ring (8MR) pore opening with increasing dehydration temperature.
Figure 4: Sorption of molecules of various sizes with lattice contraction of Sr-exchanged ETS-4.
Figure 5: The molecular gate effect.

References

  1. Hammonds, K. D., Heine, V. & Dove, M. T. Rigid-unit modes and the quantitative determination of the flexibility possessed by zeolite frameworks. J. Phys. Chem. B 102, 1759–1767 (1998).

    Article  CAS  Google Scholar 

  2. Mentzen, B. F. & Gelin, P. The silicalite p-xylene system. 1. Flexibility of the MFI framework and sorption mechanism observed during p-xylene pore-filling by X-ray powder diffraction at room temperature. Mater. Res. Bull. 30, 373–380 (1995).

    Article  CAS  Google Scholar 

  3. Nenoff, T. M. et al. Flexibility of the zeolite RHO framework. In situ X-ray and neutron powder structural characterization of cation exchanged BePO and BeAsO RHO analogs. J. Phys. Chem. 102, 14256–14264 (1996).

    Article  Google Scholar 

  4. Johnson, G. M. et al. Flexibility and cation distribution upon lithium exchange of aluminosilicate and aluminogermanate materials with RHO topologies. Chem. Mater. 11, 2780–2787 (1999).

    Article  CAS  Google Scholar 

  5. Kuznicki, S. M. Large-pored crystalline titanium molecular sieve zeolites. US Patent No. 4853202 (1989).

  6. Kuznicki, S. M. & Thrush, K. A. Large-pored molecular sieves with charged octahedral titanium and charged tetrahedral aluminum sites. US Patent No. 5244650 (1993).

  7. Kuznicki, S. M. & Thrush, K. A. Large-pored molecular sieves containing at least one octahedral site comprising titanium and at least silicon as a tetrahedral site. US Patent No. 5208006 (1993).

  8. Kuznicki, S. M. Preparation of small-pored crystalline titanium molecular sieve zeolites. US Patent No. 4938939 (1990).

  9. Anderson, M. W. et al. Structure of the microporous titanosilicate ETS-10. Nature 367, 347–351 (1994).

    Article  ADS  CAS  Google Scholar 

  10. Anderson, M. W. et al. Microporous titanosilicate ETS-10, a structural survey. Phil. Mag. B 71, 813–841 (1995).

    Article  ADS  CAS  Google Scholar 

  11. Wang, X. & Jacobson, A. J. Crystal structure of the microporous titanosilicate ETS-10 refined from single crystal X-ray diffraction data. Chem. Commun. 973–974 (1999).

  12. Anderson, M. W. et al. Isomorphous substitution in the microporous titanosilicate ETS-10. Microporous Mater. 6, 195–204 (1996).

    Article  CAS  Google Scholar 

  13. Eldewik, A., Luca, V., Singh, N. K. & Howe, R. F. Iron substitution in the microporous titanosilicate ETS-10. Proc. Int. Zeolite Conf. 3, 1507–1514 (1998).

    Google Scholar 

  14. Lamberti, C. Electron-hole reduced effective mass in monoatomic –OTiOTiO– quantum wires embedded in the siliceous crystalline matrix of ETS-10. Microporous Mesoporous Mater. 30, 155–163 (1999).

    Article  CAS  Google Scholar 

  15. Rocha, J. & Anderson, M. W. Microporous titanosilicates and other novel mixed octahedral-tetrahedral framework oxides. Eur. J. Inorg. Chem. 801–818 (2000).

  16. Bordiga, S. et al. Stoichiometric and sodium-doped titanium silicate molecular sieve containing atomically defined -OTiOTiO- chains: Quantum ab initio calculations, spectroscopic properties, and reactivity. J. Chem. Phys. 112, 3859–3867 (2000).

    Article  ADS  CAS  Google Scholar 

  17. Kuznicki, S. M., Bell, V. A., Petrovic, I. & Desai, B. T. Small-pored crystalline titanium molecular sieve zeolites and their use in gas separation processes. US Patent No. 6068682 (2000).

  18. Sandomirskii, P. A. & Belov, N. V. The OD structure of zorite. Sov. Phys. Crystallogr. 24, 686–693 (1979).

    Google Scholar 

  19. Mer'kov, A. N. et al. Raite and zorite, new minerals from the Lovozero tundra. Zap. Vses. Mineral. Obshchest. 102, 54–62 (1973).

    CAS  Google Scholar 

  20. Philippou, A. & Anderson, M. W. Structural investigation of ETS-4. Zeolites 16, 98–107 (1996).

    Article  CAS  Google Scholar 

  21. Braunbarth, C. et al. Structure of strontium ion exchanged ETS-4 microporous molecular sieves. Chem. Mater. 12, 1857–1865 (2000).

    Article  CAS  Google Scholar 

  22. McCusker, L. B. in Comprehensive Supramolecular Chemistry, Solid-State Supramolecular Chemistry: Two- and Three- Dimensional Inorganic Networks (eds Alberti, G. & Bein, T.) 393–423 (Pergamon, New York, 1996).

    Google Scholar 

  23. Cruciani, G., De Luca, P., Nastro, A. & Pattison, P. Rietveld refinement of the zorite structure of ETS-4 molecular sieves. Microporous Mesoporous Mater. 21, 143–153 (1998).

    Article  CAS  Google Scholar 

  24. Bieniok, A. & Hammonds, K. D. Rigid unit modes and the phase transition and structural distortions of zeolite rho. Microporous Mesoporous Mater. 25, 193–200 (1998).

    Article  CAS  Google Scholar 

  25. Bieniok, A. & Baur, W. H. A large volume contraction accompanies the low- to high- temperature transition of zeolite Sr-RHO. J. Solid State Chem. 90, 173–182 (1991).

    Article  ADS  CAS  Google Scholar 

  26. Depmeier, W. in Molecular Sieves Vol. 2, Structures and Structure Determination (eds Karge, H. J. & Weitkamp, J.) 113–140 (Springer, Berlin, 1999).

    Book  Google Scholar 

  27. Le Bail, A., Duroy, H. & Fourquet, J. L. Ab-initio structure determination of LiSbWO6 by X-ray powder diffraction. Mater. Res. Bull. 23, 447–452 (1988).

    Article  CAS  Google Scholar 

  28. Young, R. A. (ed.) The Rietveld Method (Oxford Univ. Press, Oxford, 1993).

    Google Scholar 

  29. Larson, A. C. & von Dreele, R. B. GSAS Report LAUR 86-784 (Los Alamos National Laboratory, 1986).

    Google Scholar 

  30. Breck, D. W. Zeolite Molecular Sieves (Wiley, New York, 1974).

    Google Scholar 

  31. Mitariten, M. & Dolan, W. Nitrogen removal from natural gas with molecular gate technology. Proc. Laurance Reid Gas Cond. Conf. 51, 1–16 (2001).

    Google Scholar 

  32. Abrams, L. & Corbin, D. R. in Topics in Inclusion Science Vol. 6, Inclusion Chemistry with Zeolites: Nanoscale Materials by Design (eds Herron, N. & Corbin, D. R.) 4–6 (Kluwer, Dordrecht, 1995).

    Google Scholar 

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Acknowledgements

We thank J. Curran for discussions and assistance in the preparation of the manuscript, and VTI Corp. for the data of Fig. 5. This work was supported by ATP/NIST, the David and Lucile Packard Foundation and NSF-CTS.

Author information

Authors and Affiliations

  1. Strategic Technology Group, Engelhard Corporation, 101 Wood Avenue, Iselin, 08830, New Jersey, USA

    Steven M. Kuznicki, Valerie A. Bell & Richard M. Jacubinas

  2. Department of Chemical Engineering, 159 Goessmann Laboratory, University of Massachusetts, Amherst, 01003, Massachusetts, USA

    Sankar Nair, Hugh W. Hillhouse, Carola M. Braunbarth & Michael Tsapatsis

  3. NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, 20899-8562, Maryland, USA

    Brian H. Toby

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Correspondence to Steven M. Kuznicki.

Supplementary information

Figures

Figure 1a

(GIF 18.5 KB)

Rietveld refinement of Sr-ETS-4 thermally treated at 150°C showing observed, calculated and difference plots from neutron diffraction data. Tick marks indicate possible Cmmm reflections.

Figure 1b

(GIF 18.1 KB)

Rietveld refinement of Sr-ETS-4 thermally treated at 200°C showing observed, calculated and difference plots from neutron diffraction data. Tick marks indicate possible Cmmm reflections.

Figure 1c

(GIF 18.7 KB)

Rietveld refinement of Sr-ETS-4 thermally treated at 250°C showing observed, calculated and difference plots from neutron diffraction data. Tick marks indicate possible Cmmm reflections.

Figure 1d

(GIF 26.3 KB)

Rietveld refinement of Sr-ETS-4 thermally treated at 300°C showing observed, calculated and difference plots from neutron diffraction data. Tick marks indicate possible Cmmm reflections.

Figure 2

(GIF 23.7 KB)

Powder X-ray diffraction data showing the stability of framework contraction. (a) Room-temperature data before thermal treatment. (b) Two overlaying traces are shown for samples after thermal treatment at 330°C. One is immediately after thermal treatment and the overlay is after 12 days of exposure to humid room-temperature air. After 12 days only a small shift to smaller angles (larger d-spacing) is observed.

Tables

Table 1a. Atomic parameters for Sr-ETS-4 structure thermally treated to 150°C in space group Cmmm with lattice constants a = 23.0271(32), b = 7.0473(7), c = 6.6670(7) Å, a= b= g= 90°. Weighted residual Rwp = 3.42 %.
Full size table
Table 1b. Atomic parameters for Sr-ETS-4 structure thermally treated to 200°C in space group Cmmm with lattice constants a = 23.0030(4), b = 6.9670(9), c = 6.6471(9) Å, a= b= g= 90°. Weighted residual Rwp = 4.43 %.
Full size table
Table 1c. Atomic parameters for Sr-ETS-4 structure thermally treated to 250°C in space group Cmmm with lattice constants a = 22.9680(4), b = 6.8231(9), c = 6.6377(9) Å, a= b= g= 90°. Weighted residual Rwp = 4.69%.
Full size table
Table 1d. Atomic parameters for Sr-ETS-4 structure thermally treated to 300ºC in space group Cmmm with lattice constants a = 22.9250(26), b = 6.6121(15), c = 6.5975(24) Å, a = b = g = 90º. Weighted residual Rwp = 5.01%.
Full size table

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Kuznicki, S., Bell, V., Nair, S. et al. A titanosilicate molecular sieve with adjustable pores for size-selective adsorption of molecules. Nature 412, 720–724 (2001). https://doi.org/10.1038/35089052

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