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  • Review Article
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Catalysts for nitrogen reduction to ammonia

Nature Catalysis volume 1, pages 490–500 (2018)Cite this article

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Abstract

The production of synthetic ammonia remains dependent on the energy- and capital-intensive Haber–Bosch process. Extensive research in molecular catalysis has demonstrated ammonia production from dinitrogen, albeit at low production rates. Mechanistic understanding of dinitrogen reduction to ammonia continues to be delineated through study of molecular catalyst structure, as well as through understanding the naturally occurring nitrogenase enzyme. The transition to Haber–Bosch alternatives through robust, heterogeneous catalyst surfaces remains an unsolved research challenge. Catalysts for electrochemical reduction of dinitrogen to ammonia are a specific focus of research, due to the potential to compete with the Haber–Bosch process and reduce associated carbon dioxide emissions. However, limited progress has been made to date, as most electrocatalyst surfaces lack specificity towards nitrogen fixation. In this Review, we discuss the progress of the field in developing a mechanistic understanding of nitrogenase-promoted and molecular catalyst-promoted ammonia synthesis and provide a review of the state of the art and scientific needs for heterogeneous electrocatalysts.

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Fig. 1: Nitrogenase enzyme structure and functions.
Fig. 2: Single electron–proton transfer model for nitrogenase-mediated nitrogen fixation.
Fig. 3: Associative nitrogen reduction pathways.
Fig. 4: Computational predictions and theory-based limitations for heterogenous (electro)catalysts.

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Acknowledgements

S.L.F. and L.F.G. gratefully acknowledge support from the US Department of Agriculture Small Business Innovation Research Program, under award # EC-015996-02. S.I.P.B., R.D., S.M., M.J.J., J.N.R. and L.F.G. gratefully acknowledge support from the US Department of Energy, Office of Science, Basic Energy Sciences, Catalysis Science Program, under award # DE-SC0016529. R.D.M. and S.D.M. thank the Army Research Office Multidisciplinary University Research Initiative (MURI) (W911NF-14-1-0263) for funding.

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  1. These authors contributed equally: Shelby L. Foster, Sergio I. Perez Bakovic.

Authors and Affiliations

  1. University of Arkansas, Ralph E. Martin Department of Chemical Engineering, Fayetteville, AR, USA

    Shelby L. Foster, Sergio I. Perez Bakovic & Lauren F. Greenlee

  2. Case Western Reserve University, Department of Chemical and Biomolecular Engineering, Cleveland, OH, USA

    Royce D. Duda & Julie N. Renner

  3. Department of Chemical Engineering, Penn State University, University Park, PA, USA

    Sharad Maheshwari & Michael J. Janik

  4. Department of Chemistry, University of Utah, Salt Lake City, UT, USA

    Ross D. Milton & Shelley D. Minteer

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Foster, S.L., Bakovic, S.I.P., Duda, R.D. et al. Catalysts for nitrogen reduction to ammonia. Nat Catal 1, 490–500 (2018). https://doi.org/10.1038/s41929-018-0092-7

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