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Ionic liquids and eutectic mixtures as solvent and template in synthesis of zeolite analogues

Nature volume 430, pages 10121016 (26 August 2004) | Download Citation

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Abstract

The challenges associated with synthesizing porous materials1 mean that new classes of zeolites (zeotypes)—such as aluminosilicate zeolites2,3 and zeolite analogues4—together with new methods of preparing known zeotypes5, continue to be of great importance. Normally these materials are prepared hydrothermally with water as the solvent in a sealed autoclave under autogenous pressure6. The reaction mixture usually includes an organic template or ‘structure-directing agent’ that guides the synthesis pathway towards particular structures. Here we report the preparation of aluminophosphate zeolite analogues by using ionic liquids7 and eutectic mixtures8. An imidazolium-based ionic liquid acts as both solvent and template, leading to four zeotype frameworks under different experimental conditions. The structural characteristics of the materials can be traced back to the solvent chemistry used. Because of the vanishingly low vapour pressure of ionic liquids, synthesis takes place at ambient pressure, eliminating safety concerns associated with high hydrothermal pressures. The ionic liquid can also be recycled for further use. A choline chloride/urea eutectic mixture8 is also used in the preparation of a new zeotype framework.

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Acknowledgements

We thank C. Hardacre (Queen's University, Belfast) and D. Cole-Hamilton (University of St Andrews) for discussions. We thank the CCLRC and S. Teat for access to the Synchrotron Radiation Source (Daresbury) and the EPSRC and D. Apperley for access to solid-state NMR. R.E.M. was supported by a Royal Society University Research Fellowship.

Author information

Affiliations

  1. School of Chemistry, University of St Andrews, Purdie Building, St Andrews KY16 9ST, UK

    • Emily R. Cooper
    • , Christopher D. Andrews
    • , Paul S. Wheatley
    • , Paul B. Webb
    • , Philip Wormald
    •  & Russell E. Morris

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Competing interests

The authors declare that they have no competing financial interests.

Corresponding author

Correspondence to Russell E. Morris.

Supplementary information

Word documents

  1. 1.

    Supplementary Methods

    An extended explanation of the characterisation of all materials, including single crystal X-ray diffraction, magic angle spinning NMR and thermal analysis. The file contains 9 figures showing the structures of materials SIZ-3 and SIZ-4, powder X-ray diffraction of SIZ-5 and AlPO-CJ2, MAS NMR spectra and thermal analysis traces of all SIZ-n materials and 8 tables of crystallography details and atomic coordinates for SIZ-1, SIZ-2, SIZ-3 and SIZ-4. It also includes a description of the chemistry of ionic liquids and ionic liquid/water mixtures.

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https://doi.org/10.1038/nature02860

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