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General synthesis of single-atom catalysts with high metal loading using graphene quantum dots

Nature Chemistry volume 13, pages 887–894 (2021)Cite this article

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Abstract

Transition-metal single-atom catalysts present extraordinary activity per metal atomic site, but suffer from low metal-atom densities (typically less than 5 wt% or 1 at.%), which limits their overall catalytic performance. Here we report a general method for the synthesis of single-atom catalysts with high transition-metal-atom loadings of up to 40 wt% or 3.8 at.%, representing several-fold improvements compared to benchmarks in the literature. Graphene quantum dots, later interweaved into a carbon matrix, were used as a support, providing numerous anchoring sites and thus facilitating the generation of high densities of transition-metal atoms with sufficient spacing between the metal atoms to avoid aggregation. A significant increase in activity in electrochemical CO2 reduction (used as a representative reaction) was demonstrated on a Ni single-atom catalyst with increased Ni loading.

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Fig. 1: Schematic illustration of the synthesis process of single-atom catalysts using different strategies.
Fig. 2: Synthesis and characterization of atomically dispersed iridium catalyst with iridium content of approximately 41 wt% and 3.84 at.%.
Fig. 3: Characterization of atomically dispersed iridium catalyst with iridium content of ~41 wt%.
Fig. 4: Generality of the GQD-assisted strategy for synthesizing atomically dispersed TM catalysts with high metal content.

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The authors declare that all of the data supporting the findings of this study are available within the paper and the Supplementary Information, and also from the corresponding authors upon reasonable request. Source data are provided with this paper.

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Acknowledgements

This work was supported by Rice University and the Welch Foundation Research Grant C-2051-20200401. H.W. is a CIFAR Azrieli Global Scholar in the Bio-inspired Solar Energy Program. C.X. acknowledges support from a J. Evans Attwell-Welch Postdoctoral Fellowship. C.X. acknowledges the University of Electronic Science and Technology of China for startup funding (A1098531023601264). This work was performed in part at the Shared Equipment Authority at Rice University. H.N.A. acknowledges support from King Abdullah University of Science and Technology. XAS and PDF measurements were conducted at the Canadian Light Source, which is supported by the Natural Sciences and Engineering Research Council of Canada (NSERC), National Research Council Canada (NRC) and University of Saskatchewan. Electron microscopy was conducted at the Center for Nanophase Materials Sciences, which is a U.S. Department of Energy Office of Science User Facility.

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Authors and Affiliations

  1. Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA

    Chuan Xia, Yunrui Qiu, Yang Xia, Peng Zhu, Xiao Zhang, Zhenyu Wu, Jung Yoon (Timothy) Kim & Haotian Wang

  2. Smalley-Curl Institute, Rice University, Houston, TX, USA

    Chuan Xia

  3. School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu, P. R. China

    Chuan Xia

  4. Canadian Light Source, University of Saskatchewan, Saskatoon, Saskatchewan, Canada

    Graham King, Mohsen Shakouri, Emilio Heredia & Yongfeng Hu

  5. Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA

    David A. Cullen

  6. Materials Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia

    Dongxing Zheng, Peng Li & Husam N. Alshareef

  7. Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, P. R. China

    Peixin Cui

  8. Department of Materials Science and Nano-Engineering, Rice University, Houston, TX, USA

    Haotian Wang

  9. Department of Chemistry, Rice University, Houston, TX, USA

    Haotian Wang

  10. Azrieli Global Scholar, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario, Canada

    Haotian Wang

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  1. Chuan Xia
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Contributions

The project was conceptualized by C.X. and H.W. and supervised by H.W. and Y.H. Catalysts were synthesized by C.X. with the help of Y.Q.; C.X., Y.Q. and P.Z. conducted the catalytic tests and the related data processing. Materials characterization and analysis were performed by C.X. with the help of P.Z., Y.X., X.Z., Z.W., D.Z., P.L., D.A.C. and J.Y.K. The XAS test and analysis was performed by M.S., E.H., P.C. and Y.H. PDF was performed by G.K.; H.N.A provided suggestions for this study. C.X. and H.W. wrote the manuscript with input from all the authors.

Corresponding authors

Correspondence to Chuan Xia, Yongfeng Hu or Haotian Wang.

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The authors declare no competing interests.

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Peer review information Nature Chemistry thanks Aiqin Wang, Yuen Wu and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Xia, C., Qiu, Y., Xia, Y. et al. General synthesis of single-atom catalysts with high metal loading using graphene quantum dots. Nat. Chem. 13, 887–894 (2021). https://doi.org/10.1038/s41557-021-00734-x

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