Letter | Published:

Mild oxidation of methane to methanol or acetic acid on supported isolated rhodium catalysts

Nature volume 551, pages 605608 (30 November 2017) | Download Citation


An efficient and direct method of catalytic conversion of methane to liquid methanol and other oxygenates would be of considerable practical value. However, it remains an unsolved problem in catalysis, as typically it involves expensive1,2,3,4 or corrosive oxidants or reaction media5,6,7,8 that are not amenable to commercialization. Although methane can be directly converted to methanol using molecular oxygen under mild conditions in the gas phase, the process is either stoichiometric (and therefore requires a water extraction step)9,10,11,12,13,14,15 or is too slow and low-yielding16 to be practical. Methane could, in principle, also be transformed through direct oxidative carbonylation to acetic acid, which is commercially obtained through methane steam reforming, methanol synthesis, and subsequent methanol carbonylation on homogeneous catalysts17,18. However, an effective catalyst for the direct carbonylation of methane to acetic acid, which might enable the economical small-scale utilization of natural gas that is currently flared or stranded, has not yet been reported. Here we show that mononuclear rhodium species, anchored on a zeolite or titanium dioxide support suspended in aqueous solution, catalyse the direct conversion of methane to methanol and acetic acid, using oxygen and carbon monoxide under mild conditions. We find that the two products form through independent pathways, which allows us to tune the conversion: three-hour-long batch-reactor tests conducted at 150 degrees Celsius, using either the zeolite-supported or the titanium-dioxide-supported catalyst, yield around 22,000 micromoles of acetic acid per gram of catalyst, or around 230 micromoles of methanol per gram of catalyst, respectively, with selectivities of 60–100 per cent. We anticipate that these unusually high activities, despite still being too low for commercial application, may guide the development of optimized catalysts and practical processes for the direct conversion of methane to methanol, acetic acid and other useful chemicals.

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  1. 1.

    et al. Direct catalytic conversion of methane to methanol in an aqueous medium by using copper-promoted Fe-ZSM-5. Angew. Chem. Int. Ed. Engl. 51, 5129–5133 (2012)

  2. 2.

    et al. Elucidation and evolution of the active component within Cu/Fe/ZSM-5 for catalytic methane oxidation: from synthesis to catalysis. ACS Catal. 3, 689–699 (2013)

  3. 3.

    , , & Heterogeneous formulation of the tricopper complex for efficient catalytic conversion of methane into methanol at ambient temperature and pressure. Energy Environ. Sci. 9, 1361–1374 (2016)

  4. 4.

    Unconventional chemistry for unconventional natural gas. Science 338, 340–342 (2012)

  5. 5.

    , , & Activation of saturated hydrocarbons. Deuterium-hydrogen exchange in solutions of transition metal complexes. Russ. J. Phys. Chem. A. 43, 1222–1223 (1969)

  6. 6.

    et al. Platinum catalysts for the high-yield oxidation of methane to a methanol derivative. Science 280, 560–564 (1998)

  7. 7.

    et al. Functionalisation of methane under dioxygen and carbon monoxide catalyzed by rhodium complexes: oxidation and oxidative carbonylation. J. Mol. Catal. Chem. 169, 89–98 (2001)

  8. 8.

    , , , & Catalytic, oxidative condensation of CH4 to CH3COOH in one step via CH activation. Science 301, 814–818 (2003)

  9. 9.

    , , , & Selective oxidation of methane by the bis(μ-oxo)dicopper core stabilized on ZSM-5 and mordenite zeolites. J. Am. Chem. Soc. 127, 1394–1395 (2005)

  10. 10.

    , , & Selective anaerobic oxidation of methane enables direct synthesis of methanol. Science 356, 523–527 (2017)

  11. 11.

    et al. Single-site trinuclear copper oxygen clusters in mordenite for selective conversion of methane to methanol. Nat. Commun. 6, 7546 (2015)

  12. 12.

    et al. Methane to acetic acid over Cu-exchanged zeolites: mechanistic insights from a site-specific carbonylation reaction. J. Am. Chem. Soc. 137, 1825–1832 (2015)

  13. 13.

    , , , & Room-temperature oxidation of methane by α-oxygen and extraction of products from the FeZSM-5 surface. J. Phys. Chem. C 115, 2155–2161 (2011)

  14. 14.

    , , & Oxidation of methane to methanol and formaldehyde over Co-ZSM-5 molecular sieves: tuning the reactivity and selectivity by alkaline and acid treatments of the zeolite ZSM-5 agglomerates. Micropor. Mesopor. Mater. 138, 176–183 (2011)

  15. 15.

    et al. Conversion of methane to methanol with a bent mono(μ-oxo)dinickel anchored on the internal surfaces of micropores. Langmuir 30, 8558–8569 (2014)

  16. 16.

    , , & Catalytic oxidation of methane into methanol over copper-exchanged zeolites with oxygen at low temperature. ACS Cent. Sci. 2, 424–429 (2016)

  17. 17.

    & Novel catalysts for the low-pressure carbonylation of methanol to acetic acid. Chem. Commun. 1578a (1968)

  18. 18.

    & Direct catalytic conversion of methane to acetic acid in an aqueous medium. Nature 368, 613–615 (1994)

  19. 19.

    , & Isolated metal active site concentration and stability control catalytic CO2 reduction selectivity. J. Am. Chem. Soc. 137, 3076–3084 (2015)

  20. 20.

    & Polycarbonyls of Rh+ formed after interaction of CO with Rh–MFI: an FTIR spectroscopic study. Phys. Chem. Chem. Phys. 5, 655–661 (2003)

  21. 21.

    et al. Time-resolved, in situ DRIFTS/EDE/MS studies on alumina-supported rhodium catalysts: effects of ceriation and zirconiation on rhodium–CO interactions. ChemPhysChem 15, 3049–3059 (2014)

  22. 22.

    et al. Light alkane oxidation using catalysts prepared by chemical vapour impregnation: tuning alcohol selectivity through catalyst pre-treatment. Chem. Sci. 5, 3603–3616 (2014)

  23. 23.

    et al. Strategies for the direct catalytic valorization of methane using heterogeneous catalysis: challenges and opportunities. ACS Catal. 6, 2965–2981 (2016)

  24. 24.

    et al. NMR-spectroscopic evidence of intermediate-dependent pathways for acetic acid formation from methane and carbon monoxide over a ZnZSM-5 zeolite catalyst. Angew. Chem. Int. Ed. 51, 3850–3853 (2012)

  25. 25.

    Recent fundamental studies on migratory insertion into metal-carbon bonds. Coord. Chem. Rev. 155, 209–243 (1996)

  26. 26.

    , , & Density functional theory study of oxygen-atom insertion into metal–methyl bonds of iron(ii), ruthenium(ii), and osmium(ii) complexes: study of metal-mediated C–O bond formation. Inorg. Chem. 53, 2968–2975 (2014)

  27. 27.

    , , , & Application of metabolic controls for the maximization of lipid production in semicontinuous fermentation. Proc. Natl Acad. Sci. USA 114, E5308–E5316 (2017)

  28. 28.

    , & Atomically dispersed Au–(OH)x species bound on titania catalyze the low-temperature water-gas shift reaction. J. Am. Chem. Soc. 135, 3768–3771 (2013)

  29. 29.

    , , , & Hydrophobic zeolites for biofuel upgrading reactions at the liquid–liquid interface in water/oil emulsions. J. Am. Chem. Soc. 134, 8570–8578 (2012)

  30. 30.

    et al. Stability of zeolites in hot liquid water. J. Phys. Chem. C 114, 19582–19595 (2010)

  31. 31.

    et al. Highly sensitive methane catalytic combustion micro-sensor based on mesoporous structure and nano-catalyst. Nanoscale 5, 9720–9725 (2013)

  32. 32.

    et al. In situ surface chemistries and catalytic performances of ceria doped with palladium, platinum, and rhodium in methane partial oxidation for the production of syngas. ACS Catal. 3, 2627–2639 (2013)

  33. 33.

    , & A general approach to mono- and bimetallic organometallic nanoparticles. Chem. Sci. 5, 4196–4203 (2014)

  34. 34.

    Tris(guanidinato)complexes of iridium and rhodium in the oxidation states +III and +IV: synthesis, characterization, and reactivity. PhD thesis, Univ. of Iowa, (2011)

  35. 35.

    et al. Promotion effects in the oxidation of CO over zeolite-supported Rh nanoparticles. J. Phys. Chem. C 112, 9394–9404 (2008)

  36. 36.

    , & Isostructural zeolite-supported rhodium and iridium complexes: tuning catalytic activity and selectivity by ligand modification. ACS Catal. 5, 5647–5656 (2015)

  37. 37.

    , , & Solubility of gases in water confined in nanoporous materials: ZSM-5, MCM-41, and MIL-100. J. Phys. Chem. C 119, 21547–21554 (2015)

  38. 38.

    et al. High activity and stability in the cross-coupling of aryl halides with disulfides over Cu-doped hierarchically porous zeolite ZSM-5. Chem. Commun. 51, 5890–5893 (2015)

  39. 39.

    et al. Mesoporous ZSM-5 zeolite-supported Ru nanoparticles as highly efficient catalysts for upgrading phenolic biomolecules. ACS Catal. 5, 2727–2734 (2015)

  40. 40.

    , , & Stability and activity of doped transition metal zeolites in the hydrothermal processing. Front. Energy Res. 3, 51 (2015)

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The financial support of this work by the Department of Energy, DOE/ARPA-e grant DE-AR0000433, under subcontract from MIT, is gratefully acknowledged. The XAS work used resources of the Advanced Photon Source, a US Department of Energy (DOE) Office of Science, User Facility operated for the DOE Office of Science by Argonne National Laboratory under contract DE-AC02-06CH11357. Aberration-corrected electron microscopy research at Oak Ridge National Laboratory was sponsored by the US Department of Energy, Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Office, Propulsion Materials Program.

Author information

Author notes

    • Junjun Shan

    Present address: NICE America Research, Inc., Mountain View, California 94043, USA.

    • Junjun Shan
    •  & Mengwei Li

    These authors contributed equally to this work.


  1. Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts 02155, USA

    • Junjun Shan
    • , Mengwei Li
    •  & Maria Flytzani-Stephanopoulos
  2. Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA

    • Lawrence F. Allard
  3. X-ray Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA

    • Sungsik Lee


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J.S. conceived the research, designed the experiments, characterized the samples and drafted the manuscript. M.L. conceived the research and performed catalytic evaluation. M.F.-S. conceived the research and designed the experiments. L.F.A was responsible for the STEM characterization. S.L. helped with the XANES and EXAFS measurements and the interpretation of the results. All the authors discussed the results and participated in writing the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Maria Flytzani-Stephanopoulos.

Reviewer Information Nature thanks E. Pidko and the other anonymous reviewer(s) for their contribution to the peer review of this work.

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