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Atomically dispersed iridium on MgO(111) nanosheets catalyses benzene–ethylene coupling towards styrene

Nature Catalysis volume 4, pages 968–975 (2021)Cite this article

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Abstract

Single-atom catalysis is recognized as a frontier of heterogeneous catalysis for its efficient utilization of metals and the possibility to engender unusual reactivity. Yet, despite the observation of single atoms, understanding their coordination structures and developing structure–property relationships remains challenging due to the structural complexity of support surfaces. Here, using single-crystalline MgO(111) two-dimensional nanosheets and a surface organometallic chemistry method, we describe the formation of highly dispersed Ir(III) sites (isolated at 0.1 wt%, and Ir pairs and trimers at 1 wt%) with well-defined coordination structures. These species display unique catalytic properties in the coupling reaction of benzene and ethylene to form styrene, a reactivity that contrasts with conventional homogeneous and heterogeneous iridium catalysts that yield ethylbenzene. The similar activities for high- and low-loading catalysts suggest that iridium sites, whether isolated or in the form of clusters (for example Ir3), have similar activity, consistent with the involvement of surface dynamics.

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Fig. 1: Materials preparation and characterization.
Fig. 2: Characterization of Ir/MgO-cal.
Fig. 3: Reaction mechanism study.
Fig. 4: Characterization of spent catalysts.

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Data availability

The data supporting the findings of this study are available in the manuscript and its Supplementary Information or from the corresponding authors upon request.

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Acknowledgements

P. Liu acknowledges support from the ETHZ Postdoctoral Fellowship Program, the Marie Curie Actions for People COFUND Program, ShanghaiTech University start-up funding and the Shanghai Pujiang Program. We are grateful to ScopeM (ETH Zürich) for access to the electron microscopy facilities. We also thank PSI for access to the Swiss Light Source SuperXAS beamline to make the XAS measurements. We acknowledge S. Zhang for the XPS measurements and N. Zheng for offering experiment facilities during the revision.

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Authors and Affiliations

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

    Pengxin Liu, Deni Mance & Christophe Copéret

  2. School of Physical Science and Technology, ShanghaiTech University, Shanghai, China

    Pengxin Liu

  3. The Scientific Center for Optical and Electron Microscopy (ScopeM), ETH Zürich, Zürich, Switzerland

    Xing Huang

  4. College of Chemistry, Fuzhou University, Fuzhou, China

    Xing Huang

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  1. Pengxin Liu
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Contributions

P.L. and C.C. conceived the project. C.C. supervised the research; P.L. performed the preparation and most of the characterization and catalytic tests; X.H. performed the ADF-STEM measurements; D.M. performed the ssNMR measurements. All the authors discussed the results and contributed to the final manuscript.

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Correspondence to Pengxin Liu or Christophe Copéret.

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Peer review information Nature Catalysis thanks Steven Tait and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary Figs. 1–29, Tables 1–4 and References 1 and 2

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Liu, P., Huang, X., Mance, D. et al. Atomically dispersed iridium on MgO(111) nanosheets catalyses benzene–ethylene coupling towards styrene. Nat Catal 4, 968–975 (2021). https://doi.org/10.1038/s41929-021-00700-3

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