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Unveiling metal mobility in a liquid Cu–Ga catalyst for ammonia synthesis

Nature Catalysis volume 7, pages 1044–1052 (2024)Cite this article

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Abstract

The outlook for sustainable economic and ecological growth projects an ammonia economy as a key enabler to the energy transition landscape. The predominance of the Haber–Bosch process, however, as the current industrial process for producing ammonia subdues the sustainability of establishing an energy route predicated on ammonia. Here we capitalize on the inherent atomic structure of liquid metal alloys and the ability to modulate the electronic and geometric structures of liquid metal catalysts to drive the thermocatalytic synthesis of ammonia. By exploiting the mobility of the metal atoms in the liquid metal configuration and purposefully designing disordered metal catalysts, we provide insights into designing future transition metal-based catalysts that produce ammonia from gaseous nitrogen and hydrogen under mild operating conditions. The use of a molten Cu–Ga catalyst offers a dynamic metal complex with synergistic advantages that lift the activity of its constituent elements, exceeding the activity of a control Ru-based catalyst.

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Fig. 1: Ammonia synthesis using a supported Cu–Ga liquid metal catalyst.
Fig. 2: Catalytic performance of the Cu–Ga alloy.
Fig. 3: Liquid metal catalyst characterization.
Fig. 4: MD modelling.

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Data availability

All data supporting the findings of this study are available in the paper and Supplementary Information or from the corresponding authors on reasonable request. The MD trajectories are available in Supplementary Data.

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Acknowledgements

T.D. acknowledges support from the Australian Research Council (ARC) via the ARC DECRA initiative (DE190100100) and the ARC Discovery Project scheme (DP220101923). T.D. and C.J.P. acknowledge the ARC Centre of Excellence in future low-energy electronics technology via CE170100039. S.S. acknowledges support from the ARC via the ARC DECRA initiative (DE190101450). S.P.R. and N.M. acknowledge the support of the ARC under the Centre of Excellence scheme (project no. CE170100026). K.Z., T.D., J.M. and R.H. acknowledge that this research was undertaken on the XAS beamline at the Australian Synchrotron, part of ANSTO. This research was undertaken with the assistance of supercomputing resources from the National Computational Infrastructure, which is supported by the Australian Government, under the National Computational Merit Allocation Scheme (Project kl59). This research was undertaken with the assistance from QUT’s Central Analytical Research Facility supported by QUT’s Research Portfolio.

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Author notes

  1. These authors contributed equally: Karma Zuraiqi, Yichao Jin.

Authors and Affiliations

  1. School of Engineering, RMIT University, Melbourne, Victoria, Australia

    Karma Zuraiqi, Caiden J. Parker, Ken Chiang & Torben Daeneke

  2. School of Chemistry and Physics, Faculty of Science, Queensland University of Technology, Brisbane, Queensland, Australia

    Yichao Jin & Huai Yong Zhu

  3. School of Chemistry and Biotechnology, Swinburne University of Technology, Melbourne, Victoria, Australia

    Jaydon Meilak & Rosalie K. Hocking

  4. ARC Centre of Excellence in Exciton Science, School of Science, RMIT University, Melbourne, Victoria, Australia

    Nastaran Meftahi, Andrew J. Christofferson & Salvy P. Russo

  5. ARC Centre of Excellence in Future Low-Energy Electronics Technologies, School of Science, RMIT University, Melbourne, Victoria, Australia

    Michelle J. S. Spencer

  6. School of Chemical and Biomolecular Engineering, Sydney Nano Institute, The University of Sydney, Sydney, New South Wales, Australia

    Lizhuo Wang, Jun Huang & Sarina Sarina

Authors
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Contributions

K.Z., K.C., S.S. and T.D. initiated, designed and led the work. Y.J., K.Z., R.H., T.D., S.S., L.W., H.Y.Z. and J.H. developed and contributed to discussion on the methodology. Y.J., K.Z., C.J.P., J.M. and R.H. carried out the experimental work and characterization. K.Z. and Y.J. developed the visualization of the work. A.C., N.M., S.P.R. and M.J.S.S. performed the computational studies and consulted on the MD calculations. K.Z. prepared the initial manuscript. All authors revised and contributed to the final version of the manuscript.

Corresponding authors

Correspondence to Sarina Sarina or Torben Daeneke.

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Patent protection is being sought for the invention described in this paper (provisional Australia patent 2022903994).

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Nature Catalysis thanks Xiaofei Guan and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary Information

Supplementary Figs. 1–34 and Table 1.

Supplementary Data 1

MD electronic structures.

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Zuraiqi, K., Jin, Y., Parker, C.J. et al. Unveiling metal mobility in a liquid Cu–Ga catalyst for ammonia synthesis. Nat Catal 7, 1044–1052 (2024). https://doi.org/10.1038/s41929-024-01219-z

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