Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Understanding the inter-site distance effect in single-atom catalysts for oxygen electroreduction

Nature Catalysis volume 4, pages 615–622 (2021)Cite this article

Subjects

Abstract

Regulating the site density of single-atom catalysts (SACs) promotes the potential to remarkably improve the performance of electrocatalysis, such as the oxygen reduction reaction (ORR). However, the catalytic behaviour governed by individual and interacting sites is particularly elusive and has yet to be understood. Here we demonstrate the origin of the enhancement of the ORR activity of isolated Fe–N4 SACs over inter-site distances down to the subnanometre level. Strong interactions between adjacent Fe–N4 moieties alter the electronic structure when the inter-site distance is less than about 1.2 nm, resulting in increased intrinsic ORR activity. The marked improvement in site performance continues until neighbouring Fe atoms approach as close as about 0.7 nm, below which the intrinsic activity is slightly diminished. The present study highlights the significance of identifying the fundamental mechanism of the inter-site distance effect in Fe–N4 catalysts for the ORR, which may promote the full potential of densely populated SACs.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on SpringerLink
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Characterizations of Fe–N4 SACs with different dsite values.
Fig. 2: Correlation of Fe contents and site densities with different dsite values.
Fig. 3: Apparent ORR activity.
Fig. 4: The dsite-dependent active site.
Fig. 5: Identification of the dsite-dependent inter-site interaction.

Similar content being viewed by others

Data availability

All data that support the findings in this paper are available within the article and its Supplementary Information or from the corresponding authors on reasonable request.

References

  1. Yang, X.-F. et al. Single-atom catalysts: a new frontier in heterogeneous catalysis. Acc. Chem. Res. 46, 1740–1748 (2013).

    Article  CAS  PubMed  Google Scholar 

  2. Wang, A., Li, J. & Zhang, T. Heterogeneous single-atom catalysis. Nat. Rev. Chem. 2, 65–81 (2018).

    Article  CAS  Google Scholar 

  3. Peng, Y., Lu, B. & Chen, S. Carbon-supported single atom catalysts for electrochemical energy conversion and storage. Adv. Mater. 30, 1801995 (2018).

    Article  CAS  Google Scholar 

  4. Li, J. et al. Atomically dispersed manganese catalysts for oxygen reduction in proton-exchange membrane fuel cells. Nat. Catal. 1, 935–945 (2018).

    Article  CAS  Google Scholar 

  5. Jin, Z. & Bard, A. J. Atom-by-atom electrodeposition of single isolated cobalt oxide molecules and clusters for studying the oxygen evolution reaction. Proc. Natl Acad. Sci. USA 117, 12651–12656 (2020).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  6. Martinez, U. et al. Progress in the development of Fe-based PGM-free electrocatalysts for the oxygen reduction reaction. Adv. Mater. 31, 1806545 (2019).

    Article  CAS  Google Scholar 

  7. Wan, C., Duan, X. & Huang, Y. Molecular design of single-atom catalysts for oxygen reduction reaction. Adv. Energy Mater. 10, 1903815 (2020).

    Article  CAS  Google Scholar 

  8. Zhao, L. et al. Cascade anchoring strategy for general mass production of high-loading single-atomic metal-nitrogen catalysts. Nat. Commun. 10, 1278 (2019).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  9. Wang, J., Li, Z., Wu, Y. & Li, Y. Fabrication of single-atom catalysts with precise structure and high metal loading. Adv. Mater. 30, 1801649 (2018).

    Article  CAS  Google Scholar 

  10. Ji, S. et al. Chemical synthesis of single atomic site catalysts. Chem. Rev. 120, 11900–11955 (2020).

    Article  CAS  PubMed  Google Scholar 

  11. Liu, L. & Corma, A. Metal catalysts for heterogeneous catalysis: from single atoms to nanoclusters and nanoparticles. Chem. Rev. 118, 4981–5079 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  12. Li, H. et al. Synergetic interaction between neighbouring platinum monomers in CO2 hydrogenation. Nat. Nanotechnol. 13, 411–417 (2018).

    Article  CAS  PubMed  Google Scholar 

  13. Cichocka, M. O. et al. A porphyrinic zirconium metal–organic framework for oxygen reduction reaction: tailoring the spacing between active-sites through chain-based inorganic building units. J. Am. Chem. Soc. 142, 15386–15395 (2020).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  14. Sours, T., Patel, A., Nørskov, J., Siahrostami, S. & Kulkarni, A. Circumventing scaling relations in oxygen electrochemistry using metal–organic frameworks. J. Phys. Chem. Lett. 11, 10029–10036 (2020).

    Article  CAS  PubMed  Google Scholar 

  15. Guo, Y. et al. Hydrogels and hydrogel-derived materials for energy and water sustainability. Chem. Rev. 120, 7642–7707 (2020).

    Article  CAS  PubMed  Google Scholar 

  16. Fang, Z., Li, P. & Yu, G. Gel electrocatalysts: an emerging material platform for electrochemical energy conversion. Adv. Mater. 32, 2003191 (2020).

    Article  CAS  Google Scholar 

  17. Zhao, F., Bae, J., Zhou, X., Guo, Y. & Yu, G. Nanostructured functional hydrogels as an emerging platform for advanced energy technologies. Adv. Mater. 30, 1801796 (2018).

    Article  CAS  Google Scholar 

  18. Zhang, N. et al. High-purity pyrrole-type FeN4 sites as a superior oxygen reduction electrocatalyst. Energy Environ. Sci. 13, 111–118 (2020).

    Article  CAS  Google Scholar 

  19. Li, X., Rong, H., Zhang, J., Wang, D. & Li, Y. Modulating the local coordination environment of single-atom catalysts for enhanced catalytic performance. Nano Res. 13, 1842–1855 (2020).

    Article  CAS  Google Scholar 

  20. Zhang, J. et al. Controlling N-doping type in carbon to boost single-atom site Cu catalyzed transfer hydrogenation of quinoline. Nano Res. 13, 3082–3087 (2020).

    Article  CAS  Google Scholar 

  21. Kaiser, S. K., Chen, Z., Fuast Akl, D., Mitchell, S. & Pérez-Ramίrez, J. Single-atom catalysts across the periodic table. Chem. Rev. 120, 11703–11809 (2020).

    Article  CAS  PubMed  Google Scholar 

  22. Brown, A. P., Hillier, S. & Brydson, R. M. D. Quantification of Fe-oxidation state in mixed valence minerals: a geochemical application of EELS revisited. J. Phys. Conf. Ser. 902, 012016 (2017).

    Article  CAS  Google Scholar 

  23. Li, P. et al. Supramolecular confinement of single Cu atoms in hydrogel frameworks for oxygen reduction electrocatalysis with high atom utilization. Mater. Today 35, 78–86 (2020).

    Article  CAS  Google Scholar 

  24. Li, P., Jin, Z., Fang, Z. & Yu, G. A surface-strained and geometry-tailored nanoreactor that promotes ammonia electrosynthesis. Angew. Chem. Int. Ed. 59, 22610–22616 (2020).

    Article  CAS  Google Scholar 

  25. Jin, Z. & Bard, A. J. Surface interrogation of electrodeposited MnOx and CaMnO3 perovskites by scanning electrochemical microscopy: probing active sites and kinetics for the oxygen evolution reaction. Angew. Chem. Int. Ed. 60, 794–799 (2021).

    Article  CAS  Google Scholar 

  26. Li, P. et al. Probing enhanced site activity of Co–Fe bimetallic subnanoclusters derived from dual cross-linked hydrogels for oxygen electrocatalysis. ACS Energy Lett. 4, 1793–1802 (2019).

    Article  CAS  Google Scholar 

  27. Jia, Q. et al. Experimental observation of redox-induced Fe–N switching behavior as a determinant role for oxygen reduction activity. ACS Nano 9, 12496–12505 (2015).

    Article  CAS  PubMed  Google Scholar 

  28. Inaba, M. et al. Benchmarking high surface area electrocatalysts in a gas diffusion electrode: measurement of oxygen reduction activities under realistic conditions. Energy Environ. Sci. 11, 988–994 (2018).

    Article  CAS  Google Scholar 

  29. Gao, J. & Liu, B. Progress of electrochemical hydrogen peroxide synthesis over single atom catalysts. ACS Mater. Lett. 2, 1008–1024 (2020).

    Article  CAS  Google Scholar 

  30. Ramaswamy, N., Tylus, U., Jia, Q. & Mukerjee, S. Activity descriptor identification for oxygen reduction on nonprecious electrocatalysts: linking surface science to coordination chemistry. J. Am. Chem. Soc. 135, 15443–15449 (2013).

    Article  CAS  PubMed  Google Scholar 

  31. Zitolo, A. et al. Identification of catalytic sites for oxygen reduction in iron- and nitrogen-doped graphene materials. Nat. Mater. 14, 937–942 (2015).

    Article  CAS  PubMed  Google Scholar 

  32. Zhang, N. et al. High-density planar-like Fe2N6 structure catalyzes efficient oxygen reduction. Matter 3, 509–521 (2020).

    Article  Google Scholar 

  33. Yuan, K. et al. Synergetic contribution of boron and Fe–Nx species in porous carbons toward efficient electrocatalysts for oxygen reduction reaction. ACS Energy Lett. 3, 252–260 (2018).

    Article  CAS  Google Scholar 

  34. Yamamoto, T. Assignment of pre‐edge peaks in K‐edge X‐ray absorption spectra of 3d transition metal compounds: electric dipole or quadrupole? Xray Spectrom. 37, 572–584 (2008).

    Article  CAS  Google Scholar 

  35. Kramm, U. I., Lefèvre, M., Larouche, N., Schmeisser, D. & Dodelet, J.-P. Correlations between mass activity and physicochemical properties of Fe/N/C catalysts for the ORR in PEM fuel cell via 57Fe Mössbauer spectroscopy and other techniques. J. Am. Chem. Soc. 136, 978–985 (2014).

    Article  CAS  PubMed  Google Scholar 

  36. Leonard, N. D. et al. Deconvolution of utilization, site density, and turnover frequency of Fe–nitrogen–carbon oxygen reduction reaction catalysts prepared with secondary N-precursors. ACS Catal. 8, 1640–1647 (2018).

    Article  CAS  Google Scholar 

  37. Primbs, M. et al. Establishing reactivity descriptors for platinum group metal (PGM)-free Fe–N–C catalysts for PEM fuel cells. Energy Environ. Sci. 13, 2480–2500 (2020).

    Article  CAS  Google Scholar 

  38. Mineva, T. et al. Understanding active sites in pyrolyzed Fe–N–C catalysts for fuel cell cathodes by bridging density functional theory calculations and 57Fe Mössbauer spectroscopy. ACS Catal. 9, 9359–9371 (2019).

    Article  CAS  Google Scholar 

  39. Orellana, W. Catalytic properties of transition metal–N4 moieties in graphene for the oxygen reduction reaction: evidence of spin-dependent mechanisms. J. Phys. Chem. C 117, 9812–9818 (2013).

    Article  CAS  Google Scholar 

  40. Sun, Y. et al. Itinerant ferromagnetic half metallic cobalt–iron couples: promising bifunctional electrocatalysts for ORR and OER. J. Mater. Chem. A 7, 27175–27185 (2019).

    Article  CAS  Google Scholar 

  41. Sun, Y. et al. Spin-related electron transfer and orbital interactions in oxygen electrocatalysis. Adv. Mater. 32, 2003297 (2020).

    Article  CAS  Google Scholar 

  42. Suntivich, J. et al. Design principles for oxygen-reduction activity on perovskite oxide catalysts for fuel cells and metal–air batteries. Nat. Chem. 3, 546–550 (2011).

    Article  CAS  PubMed  Google Scholar 

  43. Hwang, J. et al. Perovskites in catalysis and electrocatalysis. Science 358, 751–756 (2017).

    Article  CAS  PubMed  Google Scholar 

  44. Xia, D. et al. Direct growth of carbon nanotubes doped with single atomic Fe–N4 active sites and neighboring graphitic nitrogen for efficient and stable oxygen reduction electrocatalysis. Adv. Funct. Mater. 29, 1906174 (2019).

    Article  CAS  Google Scholar 

  45. Mun, Y. et al. Versatile strategy for tuning ORR activity of a single Fe-N4 site by controlling electron-withdrawing/donating properties of a carbon plane. J. Am. Chem. Soc. 141, 6254–6262 (2019).

    Article  CAS  PubMed  Google Scholar 

  46. Luo, F. et al. P-block single-metal-site tin/nitrogen-doped carbon fuel cell cathode catalyst for oxygen reduction reaction. Nat. Mater. 19, 1215–1223 (2020).

    Article  CAS  PubMed  Google Scholar 

  47. Kulkarni, A., Siahrostami, S., Patel, A. & Nørskov, J. K. Understanding catalytic activity trends in the oxygen reduction reaction. Chem. Rev. 118, 2302–2312 (2018).

    Article  CAS  PubMed  Google Scholar 

  48. Xiao, M. et al. Climbing the apex of the ORR volcano plot via binuclear site construction: electronic and geometric engineering. J. Am. Chem. Soc. 141, 17763–17770 (2019).

    Article  CAS  PubMed  Google Scholar 

  49. Gu, J., Hsu, C.-S., Bai, L., Chen, H. M. & Hu, X. Atomically dispersed Fe3+ sites catalyze efficient CO2 electroreduction to CO. Science 364, 1091–1094 (2019).

    Article  CAS  PubMed  Google Scholar 

  50. Wang, M. et al. Over 56.55% Faradaic efficiency of ambient ammonia synthesis enabled by positively shifting the reaction potential. Nat. Commun. 10, 341 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  51. Bo, J. et al. Morphology-controlled fabrication of polypyrrole hydrogel for solid-state supercapacitor. J. Power Sources 407, 105–111 (2018).

    Article  CAS  Google Scholar 

  52. Li, P., Jin, Z., Fang, Z. & Yu, G. A single-site iron catalyst with preoccupied active center that achieves selective ammonia electrosynthesis from nitrate. Energy Environ. Sci. 14, 3522–3531 (2021).

    Article  CAS  Google Scholar 

  53. Ahn, H. S. & Bard, A. J. Switching transient generation in surface interrogation scanning electrochemical microscopy and time-of-flight techniques. Anal. Chem. 87, 12276–12280 (2015).

    Article  CAS  PubMed  Google Scholar 

Download references

Acknowledgements

G.Y. acknowledges the funding support from the US Department of Energy, Office of Science, Basic Energy Sciences under Award DE-SC0019019, the Welch Foundation Award F-1861 and the Camille Dreyfus Teacher-Scholar Award. We sincerely thank A.J. Bard and his group for the support and thoughtful discussion on SECM.

Author information

Author notes

  1. These authors contributed equally: Zhaoyu Jin, Panpan Li.

Authors and Affiliations

  1. Materials Science and Engineering Program, Texas Materials Institute, The University of Texas at Austin, Austin, TX, USA

    Zhaoyu Jin, Panpan Li, Zhiwei Fang & Guihua Yu

  2. Center for Electrochemistry, Department of Chemistry, The University of Texas at Austin, Austin, TX, USA

    Zhaoyu Jin

  3. Department of Chemical Engineering, Sichuan University, Chengdu, P.R. China

    Yan Meng & Dan Xiao

Authors
  1. Zhaoyu Jin
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Panpan Li
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Yan Meng
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Zhiwei Fang
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Dan Xiao
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Guihua Yu
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

G.Y. conceived and directed the project. Z.J. designed experiments, performed SI–SECM and simulations, and wrote the paper. P.L. conducted the synthesis of catalysts and electrochemical experiments. Y.M. and D.X. supported the characterizations and analysis. P.L. and Z.F. edited the manuscript. All authors discussed and revised the manuscript.

Corresponding authors

Correspondence to Dan Xiao or Guihua Yu.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature Catalysis thanks Hyun S. Park, Samira Siahrostami and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Figs. 1–24, Tables 1–13, Notes 1–11, Methods and References.

Supplementary Data 1

Atomic coordinates.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Jin, Z., Li, P., Meng, Y. et al. Understanding the inter-site distance effect in single-atom catalysts for oxygen electroreduction. Nat Catal 4, 615–622 (2021). https://doi.org/10.1038/s41929-021-00650-w

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41929-021-00650-w

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing