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Molecular-sieve catalysts for the selective oxidation of linear alkanes by molecular oxygen

Abstract

Terminally oxidized hydrocarbons are of considerable interest as potential feedstocks for the chemical and pharmaceutical industry, but the selective oxidation of only the terminal methyl groups in alkanes remains a challenging task. It is accomplished with high efficiency and selectivity by some enzymes; but inorganic catalysts, although inferior in overall performance under benign conditions, offer significant advantages from a processing standpoint1. Controlled partial oxidation is easier to achieve with ‘sacrificial’ oxidants, such as hydrogen peroxide2, alkyl hydroperoxides oriodosylbenzene3, than with molecular oxygen or air. These sacrificial oxidants, themselves the product of oxidation reactions, have been used in catalytic systems involving tailored transition-metal complexes in either a homogeneous state4,5,6, encapsulated in molecular sieves7,8,9 or anchored to the inner surfaces of porous siliceous supports10. Here we report the design and performance of two aluminophosphate molecular sieves containing isolated, four-coordinated Co(III) or Mn(III) ions that are substituted into the framework and act, in concert with the surrounding framework structure, as regioselective catalysts for the oxidation of linear alkanes by molecular oxygen. The catalysts operate at temperatures between 373 K and 403 K through a classical free-radical chain-autoxidation mechanism. They are thus able to use molecular oxygen as oxidant, which, in combination with their good overall performance, raises the prospect of using this type of selective inorganic catalyst for industrial oxidation processes.

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Figure 1: The performance of Co and Mn substituted molecular-sieve catalysts.
Figure 2: Kinetics of n -hexane oxidation in air over Co substituted AlPO catalysts.
Figure 3: Energy-minimized configuration (two views) adopted by n -hexane at 0 K inside an AlPO-18 framework.

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References

  1. Hill, C. L. (ed.) Activation and Functionalisation of AlkanesCh. 6–8 (Wiley, Chichester, (1989).

    Google Scholar 

  2. Tatsumi, T., Nakamura, M., Negishi, S. & Tominaga, H. Shape-selective oxidation of alkanes with H2O2catalysed by titanosilicate. J. Chem. Soc. Chem. Commun. 476–477 (1990).

  3. Smegal, J. A. & Hill, C. L. Hydrocarbon functionalisation by the (iodosylbenzene) manganese(IV) porphyrin complexes from the (tetraphenylporphyrinato) manganese(III)-iodosylbenzene catalytic hydrocarbon oxidation system. Mechanism and reaction chemistry. J. Am. Chem. Soc. 105, 3515–3521 (1983).

    Article  CAS  Google Scholar 

  4. Cook, B. R., Reinert, T. J. & Suslick, T. S. Shape selective alkane hydroxylation by metalloporphyrin catalysts. J. Am. Chem. Soc. 108, 7281–7286 (1986).

    Article  CAS  Google Scholar 

  5. Mansuy, D. Cytochrome-P450 and synthetic models. Pure Appl. Chem. 59, 759–770 (1987).

    Article  CAS  Google Scholar 

  6. Lyons, J. E., Ellis, P. E. J & Myers, W. K. J Halogenated metalloporphyrin complexes as catalysts for selective reactions of acyclic alkanes with molecular oxygen. J. Catal. 155, 59–73 (1995).

    Article  CAS  Google Scholar 

  7. Herron, N. & Tolman, C. A. Ahighly selective zeolite catalyst for hydrocarbon oxidation—a completely inorganic mimic of the alkane omega-hydroxylases. J. Am. Chem. Soc. 109, 2837–2839 (1987).

    Article  CAS  Google Scholar 

  8. Raja, R. & Ratnasamy, P. Process for the oxidation of cyclohexane to a mixture of cyclohexanol and cyclohexanone. US PatentNo. 5,767,320 (1998).

  9. Raja, R. & Ratnasamy, P. Selective oxidation with copper complexes incorporated in molecular sieves. Stud. Surf. Sci. Catal. 101, 181–190 (1996).

    Article  CAS  Google Scholar 

  10. Maschmeyer, T. et al. Designing a solid catalyst for the selective low-temperature oxidation of cyclohexane to cyclohexanone. Angew. Chem. Int. Edn 36, 1639–1642 (1997).

    Article  CAS  Google Scholar 

  11. Thomas, J. M. et al. On the nature of the active site in a CoAPO-18 solid acid catalyst. Angew. Chem. Int. Edn 33, 1871–1873 (1994).

    Article  Google Scholar 

  12. Barrett, P. A., Sankar, G., Catlow, C. R. A. & Thomas, J. M. X-ray absorption spectroscopic study of Brönsted, Lewis and redox centres in cobalt-substituted aluminium phosphate catalysts. J. Phys. Chem. 100, 8977–8985 (1996).

    Article  CAS  Google Scholar 

  13. Iton, L. E., Choi, I., Desjardins, J. A. & Maroni, V. A. Stabilisation of Co(III) in aluminophosphate molecular sieve frameworks. Zeolites 9, 535–538 (1989).

    Article  CAS  Google Scholar 

  14. Lin, S. S. & Weng, H. S. Liquid-phase oxidation of cyclohexane over CoAPO-5: Synergism effect of coreactant and solvent effect. Appl. Catal. 118, 21–31 (1994).

    Article  CAS  Google Scholar 

  15. Krauschaar-Czarnetzki, B., Hoogervorst, W. G. M. & Stork, W. H. J. Oxidation of saturated hydrocarbons involving CoAPO molecular sieves as oxidants and as catalysts. Stud. Surf. Sci. Catal. 84, 1869–1876 (1994).

    Article  Google Scholar 

  16. Tolman, C. A., Druliner, J. D., Nappa, M. J. & Herron, N. in Activation and Functionalization of Alkanes (ed. Hill, C. L.) 303–360 (Wiley, Chichester, (1989).

    Google Scholar 

  17. Kerr, J. A. Bond dissociation energies by kinetic methods. Chem. Rev. 66, 465–498 (1966).

    Article  CAS  Google Scholar 

  18. Chen, J. & Thomas, J. M. MAPO-18 (M- Mg, Zn, Co)—A new family of catalysts for the conversion of methanol to light olefins. J. Chem. Soc. Chem. Commun. 603–604 (1994).

  19. Thomas, J. M. The ineluctable need for in-situ methods of characterising solid catalysts as a prerequisite to engineering active sites. Eur. J. Chem. 3, 1557–1562 (1997).

    Article  CAS  Google Scholar 

  20. Vanoppen, D. L., De Vos, D., Genet, M. J., Rouxhet, P. G. & Jacobs, P. A. Cobalt-containing molecular-sieves as catalysts for the low conversion autoxidation of pure cyclohexane. Angew. Chem. Int. Edn 34, 560–563 (1995).

    Article  CAS  Google Scholar 

  21. Sankar, G., Raja, R. & Thomas, J. M. Redox solid catalysts for the selective oxidation of cyclohexane in air. Cat. Lett. 55, 15–23 (1998).

    Article  CAS  Google Scholar 

  22. Thomas, J. M. & Thomas, W. J. Introduction to the Principles of Heterogeneous Catalysis 383–384 (Academic, London, (1967).

    Google Scholar 

  23. Groves, J. T. Artificial enzymes—the importance of being selective. Nature 389, 329–330 (1997).

    Article  ADS  CAS  PubMed  Google Scholar 

  24. Ludwig, M. L., Metzger, A. L., Pattridge, K. A. & Stallings, W. C. Manganese superoxide dismutase from Thermus thermophilus—a structural model refined at 1.8 å resolution. J. Mol. Biol. 219, 335–358 (1991).

    Article  CAS  PubMed  Google Scholar 

  25. Barrett, P. A., Sankar, G., Jones, R. H., Catlow, C. R. A. & Thomas, J. M. Interaction of acetonitrile with cobalt-containing aluminophosphates: an x-ray absorption investigation. J. Phys. Chem. 101, 9555–9562 (1997).

    Article  CAS  Google Scholar 

  26. Freeman, C. M., Catlow, C. R. A., Thomas, J. M. & Brode, S. Computing the location and energetics of organic molecules in microporous adsorbents and catalysts—hybrid approach applied to isomeric butenes in a model zeolite. Chem. Phys. Lett. 186, 137–142 (1991).

    Article  ADS  CAS  Google Scholar 

  27. Morohashi, K., Sadano, H., Okada, Y. & Omura, T. Position specificity in n-hexane hydroxylation by two forms of cytochrome P-450 in rat liver microsomes. J. Biochem. 93, 413–419 (1983).

    Article  CAS  PubMed  Google Scholar 

  28. Hamberg, M., Samuelsson, B., Bjorkhem, I. & Danielsson, H. in Molecular Mechanisms of Oyxgen Activation (ed. Hayaishi, O.) 24–52 (Academic, New York, (1974).

    Google Scholar 

  29. Binsted, N. EXCURV 98 (CCLRC Daresbury Lab., (1998).

Download references

Acknowledgements

We thank D. W. Lewis for discussions. We also thank the UK EPSRC for a rolling grant (J.M.T.) and the Royal Commission for the Exhibition of 1851 for a research fellowship (R.R.). Molecular Simulation Inc. (MSI) is acknowledged for the provision of molecular modelling software.

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Thomas, J., Raja, R., Sankar, G. et al. Molecular-sieve catalysts for the selective oxidation of linear alkanes by molecular oxygen. Nature 398, 227–230 (1999). https://doi.org/10.1038/18417

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