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A homogeneous transition metal complex for clean hydrogen production from methanol–water mixtures

Nature Chemistry volume 5, pages 342347 (2013) | Download Citation

Abstract

The development of an efficient catalytic process that mimics the enzymatic function of alcohol dehydrogenase is critical for using biomass alcohols for both the production of H2 as a chemical energy carrier and fine chemicals under waste-free conditions. Dehydrogenation of alcohol–water mixtures into their corresponding acids with molecular hydrogen as the sole by-product from the reaction can be catalysed by a ruthenium complex with a chelating bis(olefin) diazadiene ligand. This complex, [K(dme)2][Ru(H)(trop2dad)], stores up to two equivalents of hydrogen intramolecularly, and catalyses the production of H2 from alcohols in the presence of water and a base under homogeneous conditions. The conversion of a MeOH–H2O mixture proceeds selectively to CO2/H2 gas formation under neutral conditions, thereby allowing the use of the entire hydrogen content (12% by weight). Isolation and characterization of the ruthenium complexes from these reactions suggested a mechanistic scenario in which the trop2dad ligand behaves as a chemically ‘non-innocent’ co-operative ligand.

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Acknowledgements

This work was supported by the Schweizer Nationalfonds (SNF), Eidgenössische Hochschule Zürich and the joint SNF/Deutsche Forschungsgemeinschaft research project ‘Unconventional Approaches to the Activation of Dihydrogen’ (FOR1175). H.G. thanks P. Edwards (University of Oxford) and Lotus Cars, in particular, for inspiration.

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Affiliations

  1. ETH Zürich, Department of Chemistry and Applied Biosciences, 8093 Zürich, Switzerland

    • Rafael E. Rodríguez-Lugo
    • , Mónica Trincado
    • , Matthias Vogt
    • , Friederike Tewes
    • , Gustavo Santiso-Quinones
    •  & Hansjörg Grützmacher

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Contributions

G.S-Q. performed the X-ray diffraction measurements with single crystals. All other authors planned and performed the experiments. R.E.R-L., M.T. and H.G. wrote the paper. All authors discussed the results and commented on the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to Mónica Trincado or Hansjörg Grützmacher.

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DOI

https://doi.org/10.1038/nchem.1595

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