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Near ambient N2 fixation on solid electrodes versus enzymes and homogeneous catalysts

Nature Reviews Chemistry volume 7, pages 184–201 (2023)Cite this article

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An Author Correction to this article was published on 24 February 2023

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Abstract

The Mo/Fe nitrogenase enzyme is unique in its ability to efficiently reduce dinitrogen to ammonia at atmospheric pressures and room temperature. Should an artificial electrolytic device achieve the same feat, it would revolutionize fertilizer production and even provide an energy-dense, truly carbon-free fuel. This Review provides a coherent comparison of recent progress made in dinitrogen fixation on solid electrodes, homogeneous catalysts and nitrogenases. Specific emphasis is placed on systems for which there is unequivocal evidence that dinitrogen reduction has taken place. By establishing the cross-cutting themes and synergies between these systems, we identify viable avenues for future research.

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Fig. 1: A comparison of nitrogen reduction over molecular catalysts, nitrogenase and a metal surface.
Fig. 2: The various reduction pathways through which nitrogen can be reduced to ammonia.
Fig. 3: A summary of the nitrogenase reduction scheme and proton delivery mechanism.
Fig. 4: Homogeneous nitrogen reduction.
Fig. 5: The limitations of metal electrodes in aqueous electrolytes.
Fig. 6: Lithium-mediated nitrogen reduction.

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Acknowledgements

O.W. acknowledges funding from the Engineering and Physical Sciences Research Council (EPSRC) and SFI Centre for Doctoral Training in Advanced Characterization of Materials Grant Ref: EP/S023259/1. J.B., I.E.L.S. and M.-M.T acknowledge funding from the National Research Council Canada through the Materials for Clean Fuels Challenge Program. I.E.L.S. acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 866402). A.B. and J.R. thank the Danish National Research Foundation DNRF-149 and the Carlsberg Foundation.

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  1. Department of Materials, Imperial College London, London, UK

    Olivia Westhead, Jesús Barrio & Ifan E. L. Stephens

  2. Department of Chemistry, University of Copenhagen, Copenhagen, Denmark

    Alexander Bagger & Jan Rossmeisl

  3. Department of Chemical Engineering, Imperial College London, London, UK

    Alexander Bagger & Maria-Magdalena Titirici

  4. Department of Life Sciences, Imperial College London, London, UK

    James W. Murray & Andrea Fantuzzi

  5. Department of Chemical Engineering, University College London, London, UK

    Rhodri Jervis

  6. Department of Chemistry, Imperial College London, London, UK

    Andrew Ashley

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All authors co-conceived the concept and constructed the structure for the article. O.W., J.B. and I.E.L.S. researched data for the article and wrote the initial draft. A.A., A.F., A.B. and J.R. contributed substantially to discussion of content. A.A., A.B., J.W.M., J.R., A.F., M.-M.T. and R.J. reviewed the manuscript before submission. O.W., J.B. and I.E.L.S. edited the final version for submission.

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Glossary

Faradaic efficiency

The proportion of electrons which go towards making the desired product.

Limiting potential

(UL). The minimum potential applied to make all elementary electron transfer steps downhill in free energy.

Ohmic loss

The loss of energy efficiency due to electrolyte resistance.

Overpotential

Any excess applied voltage due to kinetic factors.

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Westhead, O., Barrio, J., Bagger, A. et al. Near ambient N2 fixation on solid electrodes versus enzymes and homogeneous catalysts. Nat Rev Chem 7, 184–201 (2023). https://doi.org/10.1038/s41570-023-00462-5

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