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.

Identification of single-atom active sites in carbon-based cobalt catalysts during electrocatalytic hydrogen evolution

Abstract

Monitoring atomic and electronic structure changes on active sites under realistic working conditions is crucial for the rational design of efficient electrocatalysts. Identification of the active structure during the alkaline hydrogen evolution reaction (HER), which is critical to industrial water–alkali electrolysers, remains elusive and is a field of intense research. Here, by virtue of operando X-ray absorption spectroscopy on a uniform cobalt single-site catalyst, we report the atomic-level identification of the dynamic structure of catalytically active sites under alkaline HER. Our results reveal the formation of a high-valence HO–Co1–N2 moiety by the binding between isolated Co1–N4 sites with electrolyte hydroxide, and further unravel the preferred water adsorption reaction intermediate H2O–(HO–Co1–N2). Theoretical simulations rationalize this structural evolution and demonstrate that the highly oxidized Co sites are responsible for the catalytic performance. These findings suggest the electrochemical susceptibility of active sites, providing a coordination-engineered strategy for the advance of single-site catalysis.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Fig. 1: Operando electrochemical measurement, microstructure and HER activities of the Co1/PCN electrocatalyst.
Fig. 2: Operando XAS measurements.
Fig. 3: Structural analysis.
Fig. 4: Theoretical investigations.

Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.

References

  1. 1.

    Dresselhaus, M. & Thomas, I. Alternative energy technologies. Nature 414, 332–337 (2001).

    CAS  Article  Google Scholar 

  2. 2.

    Zou, X. & Zhang, Y. Noble metal-free hydrogen evolution catalysts for water splitting. Chem. Soc. Rev. 44, 5148–5180 (2015).

    CAS  Article  Google Scholar 

  3. 3.

    Walter, M. G. et al. Solar water splitting cells. Chem. Rev. 110, 6446–6473 (2010).

    CAS  Article  Google Scholar 

  4. 4.

    Subbaraman, R. et al. Trends in activity for the water electrolyser reactions on 3d M (Ni, Co, Fe, Mn) hydr(oxy)oxide catalysts. Nat. Mater. 11, 550–557 (2012).

    CAS  Article  Google Scholar 

  5. 5.

    Seh, Z. W. et al. Combining theory and experiment in electrocatalysis: Insights into materials design. Science 355, 146 (2017).

    Article  Google Scholar 

  6. 6.

    Subbaraman, R. et al. Enhancing hydrogen evolution activity in water splitting by tailoring Li+–Ni (OH)2–Pt interfaces. Science 334, 1256–1260 (2011).

    CAS  Article  Google Scholar 

  7. 7.

    Weng, Z. et al. Active sites of copper-complex catalytic materials for electrochemical carbon dioxide reduction. Nat. Commun. 9, 415 (2018).

    Article  Google Scholar 

  8. 8.

    Ding, K. et al. Identification of active sites in CO oxidation and water-gas shift over supported Pt catalysts. Science 350, 189–192 (2015).

    CAS  Article  Google Scholar 

  9. 9.

    Irvine, J. T. et al. Evolution of the electrochemical interface in high-temperature fuel cells and electrolysers. Nat. Energy 1, 15014 (2016).

    CAS  Article  Google Scholar 

  10. 10.

    Weng, Z. et al. Self-cleaning catalyst electrodes for stabilized CO2 reduction to hydrocarbons. Angew. Chem. Int. Ed. 56, 13135–13139 (2017).

    CAS  Article  Google Scholar 

  11. 11.

    Malta, G. et al. Identification of single-site gold catalysis in acetylene hydrochlorination. Science 355, 1399–1403 (2017).

    CAS  Article  Google Scholar 

  12. 12.

    Qiao, B. et al. Single-atom catalysis of CO oxidation using Pt1/FeOx. Nat. Chem. 3, 634–641 (2011).

    CAS  Article  Google Scholar 

  13. 13.

    Liu, P. et al. Photochemical route for synthesizing atomically dispersed palladium catalysts. Science 352, 797–801 (2016).

    CAS  Article  Google Scholar 

  14. 14.

    Zhang, H., Liu, G., Shi, L. & Ye, J. Single-atom catalysts: emerging multifunctional materials in heterogeneous catalysis. Adv. Energy Mater. 8, 1701343 (2017).

    Article  Google Scholar 

  15. 15.

    Therrien, A. J. et al. An atomic-scale view of single-site Pt catalysis for low-temperature CO oxidation. Nat. Catal. 1, 192–198 (2018).

    Article  Google Scholar 

  16. 16.

    Jones, J. et al. Thermally stable single-atom platinum-on-ceria catalysts via atom trapping. Science 353, 150–154 (2016).

    CAS  Article  Google Scholar 

  17. 17.

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

    CAS  Article  Google Scholar 

  18. 18.

    Liu, W. et al. Single-site active cobalt-based photocatalyst with a long carrier lifetime for spontaneous overall water splitting. Angew. Chem. Int. Ed. 56, 9312–9317 (2017).

    CAS  Article  Google Scholar 

  19. 19.

    Shan, J., Li, M., Allard, L. F., Lee, S. & Flytzani-Stephanopoulos, M. Mild oxidation of methane to methanol or acetic acid on supported isolated rhodium catalysts. Nature 551, 605–608 (2017).

    CAS  Article  Google Scholar 

  20. 20.

    Nie, L. et al. Activation of surface lattice oxygen in single-atom Pt/CeO2 for low-temperature CO oxidation. Science 358, 1419–1423 (2017).

    CAS  Article  Google Scholar 

  21. 21.

    Tang, Y. et al. Single rhodium atoms anchored in micropores for efficient transformation of methane under mild conditions. Nat. Commun. 9, 1231 (2018).

    Article  Google Scholar 

  22. 22.

    Lin, L. et al. Low-temperature hydrogen production from water and methanol using Pt/α-MoC catalysts. Nature 544, 80–83 (2017).

    CAS  Article  Google Scholar 

  23. 23.

    Cheng, N. et al. Platinum single-atom and cluster catalysis of the hydrogen evolution reaction. Nat. Commun. 7, 13638 (2016).

    CAS  Article  Google Scholar 

  24. 24.

    Marković, N., Schmidt, T., Stamenković, V. & Ross, P. Oxygen reduction reaction on Pt and Pt bimetallic surfaces: a selective review. Fuel Cells 1, 105–116 (2001).

    Article  Google Scholar 

  25. 25.

    Jiao, Y., Zheng, Y., Jaroniec, M. & Qiao, S. Z. Design of electrocatalysts for oxygen-and hydrogen-involving energy conversion reactions. Chem. Soc. Rev. 44, 2060–2086 (2015).

    CAS  Article  Google Scholar 

  26. 26.

    Liu, W. et al. Single-atom dispersed Co–N–C catalyst: structure identification and performance for hydrogenative coupling of nitroarenes. Chem. Sci. 7, 5758–5764 (2016).

    CAS  Article  Google Scholar 

  27. 27.

    Cao, Y. et al. Atomic insight into optimizing hydrogen evolution pathway over a Co1–N4 single-site photocatalyst. Angew. Chem. Int. Ed. 56, 12191–12196 (2017).

    CAS  Article  Google Scholar 

  28. 28.

    Fei, H. et al. General synthesis and definitive structural identification of MN4C4 single-atom catalysts with tunable electrocatalytic activities. Nat. Catal. 1, 63–72 (2018).

    Article  Google Scholar 

  29. 29.

    Zitolo, A. et al. Identification of catalytic sites in cobalt–nitrogen–carbon materials for the oxygen reduction reaction. Nat. Commun. 8, 957 (2017).

    Article  Google Scholar 

  30. 30.

    Chen, W. et al. Rational design of single molybdenum atoms anchored on N-doped carbon for effective hydrogen evolution reaction. Angew. Chem. Int. Ed. 129, 16302–16306 (2017).

    Article  Google Scholar 

  31. 31.

    Ledezma-Yanez, I. et al. Interfacial water reorganization as a pH-dependent descriptor of the hydrogen evolution rate on platinum electrodes. Nat. Energy 2, 17031 (2017).

    CAS  Article  Google Scholar 

  32. 32.

    Dou, J. et al. Operando chemistry of catalyst surfaces during catalysis. Chem. Soc. Rev. 46, 2001–2027 (2017).

    CAS  Article  Google Scholar 

  33. 33.

    Fabbri, E. et al. Dynamic surface self-reconstruction is the key of highly active perovskite nano-electrocatalysts for water splitting. Nat. Mater. 16, 925–931 (2017).

    CAS  Article  Google Scholar 

  34. 34.

    Yao, T. et al. Insights into initial kinetic nucleation of gold nanocrystals. J. Am. Chem. Soc. 132, 7696–7701 (2010).

    CAS  Article  Google Scholar 

  35. 35.

    Tao, F. F. & Salmeron, M. In situ studies of chemistry and structure of materials in reactive environments. Science 331, 171–174 (2011).

    CAS  Article  Google Scholar 

  36. 36.

    Pastor, E. et al. Spectroelectrochemical analysis of the mechanism of (photo) electrochemical hydrogen evolution at a catalytic interface. Nat. Commun. 8, 14280 (2017).

    CAS  Article  Google Scholar 

  37. 37.

    Marberger, A. et al. Time-resolved copper speciation during selective catalytic reduction of NO on Cu-SSZ-13. Nat. Catal. 1, 221–227 (2018).

    Article  Google Scholar 

  38. 38.

    Genovese, C. et al. Operando spectroscopy study of the carbon dioxide electro-reduction by iron species on nitrogen-doped carbon. Nat. Commun. 9, 935 (2018).

    Article  Google Scholar 

  39. 39.

    Sun, Z. H., Liu, Q. H., Yao, T., Yan, W. S. & Wei, S. Q. X-ray absorption fine structure spectroscopy in nanomaterials. Sci. China Mater. 58, 313–341 (2015).

    CAS  Article  Google Scholar 

  40. 40.

    Jiao, Y., Zheng, Y., Davey, K. & Qiao, S.-Z. Activity origin and catalyst design principles for electrocatalytic hydrogen evolution on heteroatom-doped graphene. Nat. Energy 1, 16130 (2016).

    CAS  Article  Google Scholar 

  41. 41.

    Mahmood, J. et al. An efficient and pH-universal ruthenium-based catalyst for the hydrogen evolution reaction. Nat. Nanotech. 12, 441–446 (2017).

    CAS  Article  Google Scholar 

  42. 42.

    Zhang, J. et al. Interface engineering of MoS2/Ni3S2 heterostructures for highly enhanced electrochemical overall-water-splitting activity. Angew. Chem. Int. Ed. 128, 6814–6819 (2016).

    Article  Google Scholar 

  43. 43.

    Yin, P. et al. Single cobalt atoms with precise N-coordination as superior oxygen reduction reaction catalysts. Angew. Chem. Int. Ed. 55, 10800–10805 (2016).

    CAS  Article  Google Scholar 

  44. 44.

    Zandi, O. & Hamann, T. W. Determination of photoelectrochemical water oxidation intermediates on haematite electrode surfaces using operando infrared spectroscopy. Nat. Chem. 8, 778–783 (2016).

    CAS  Article  Google Scholar 

  45. 45.

    Xing, T. et al. Observation of active sites for oxygen reduction reaction on nitrogen-doped multilayer graphene. ACS Nano 8, 6856–6862 (2014).

    CAS  Article  Google Scholar 

  46. 46.

    Zheng, Y. et al. Molecule-level g-C3N4 coordinated transition metals as a new class of electrocatalysts for oxygen electrode reactions. J. Am. Chem. Soc. 139, 3336–3339 (2017).

    CAS  Article  Google Scholar 

  47. 47.

    Liang, Y. Y. et al. Co3O4 nanocrystals on graphene as a synergistic catalyst for oxygen reduction reaction. Nat. Mater. 10, 780–786 (2011).

    CAS  Article  Google Scholar 

  48. 48.

    Istomin, S. Y. et al. An unusual high-spin ground state of Co3+ in octahedral coordination in brownmillerite-type cobalt oxide. Dalton Trans. 44, 10708–10713 (2015).

    CAS  Article  Google Scholar 

  49. 49.

    Zheng, X. et al. Theory-driven design of high-valence metal sites for water oxidation confirmed using in situ soft X-ray absorption. Nat. Chem. 10, 149–154 (2018).

    CAS  Article  Google Scholar 

  50. 50.

    Zheng, Y. et al. High electrocatalytic hydrogen evolution activity of an anomalous ruthenium catalyst. J. Am. Chem. Soc. 138, 16174–16181 (2016).

    CAS  Article  Google Scholar 

  51. 51.

    Zhang, J. et al. Efficient hydrogen production on MoNi4 electrocatalysts with fast water dissociation kinetics. Nat. Commun. 8, 15437 (2017).

    CAS  Article  Google Scholar 

  52. 52.

    Newville, M. IFEFFIT: interactive XAFS analysis and FEFF fitting. J. Synchrot. Radiat. 8, 322–324 (2001).

    CAS  Article  Google Scholar 

  53. 53.

    Ravel, B. & Newville, M. ATHENA, ARTEMIS, HEPHAESTUS: data analysis for X-ray absorption spectroscopy using IFEFFIT. J. Synchrot. Radiat. 12, 537–541 (2005).

    CAS  Article  Google Scholar 

  54. 54.

    Ankudinov, A., Ravel, B., Rehr, J. & Conradson, S. Real-space multiple-scattering calculation and interpretation of X-ray-absorption near-edge structure. Phys. Rev. B 58, 7565–7576 (1998).

    CAS  Article  Google Scholar 

  55. 55.

    Kresse, G. & Furthmüller, J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. Rev. B 54, 11169–11186 (1996).

    CAS  Article  Google Scholar 

  56. 56.

    Kresse, G. & Joubert, D. From ultrasoft pseudopotentials to the projector augmented-wave method. Phys. Rev. B 59, 1758–1775 (1999).

    CAS  Article  Google Scholar 

  57. 57.

    Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phy. Rev. Lett. 77, 3865–3868 (1996).

    CAS  Article  Google Scholar 

  58. 58.

    Monkhorst, H. J. & Pack, J. D. Special points for Brillouin-zone integrations. Phys. Rev. B 13, 5188–5192 (1976).

    Article  Google Scholar 

  59. 59.

    Henkelman, G., Uberuaga, B. P. & Jónsson, H. A climbing image nudged elastic band method for finding saddle points and minimum energy paths. Phy. Rev. Lett 113, 9901 (2000).

    CAS  Google Scholar 

  60. 60.

    Singh, U. P., Babbar, P., Tyagi, P. & Weyhermüller, T. A mononuclear cobalt(ii) hydroxo complex: synthesis, molecular structure, and reactivity studies. Transition Met. Chem. 33, 931–940 (2008).

    CAS  Article  Google Scholar 

Download references

Acknowledgements

This work was supported by the China Ministry of Science and Technology under contracts nos. 2017YFA0402800 and 2017YFA0208300, the National Natural Science Foundation of China (grants nos. 21471143, 21533007, 11621063 and 21703222), the Fundamental Research Funds for the Central Universities (KY2310000020 and KY2310000019, and the Youth Innovation Promotion Association CAS (CX2310000091). The authors thank NSRL, BSRF and SSRF for synchrotron beam time. Calculations were conducted on the supercomputing system in the Supercomputing Center of USTC.

Author information

Affiliations

Authors

Contributions

T.Y. and S.W. developed the idea and designed experiments. L.C., X.L., Y.C., W.L. and W.Z. performed the catalyst synthesis and characterizations, XAFS measurements and electrochemical experiments. Q.L. and J.Y. conducted and discussed the theoretical calculations. L.C., Y.L. and Y.W. performed the aberration-corrected STEM characterization. L.C., T.Y. and S.W. co-wrote the paper. All authors discussed the results and commented on the manuscript.

Corresponding authors

Correspondence to Tao Yao or Shiqiang Wei.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

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

Supplementary information

Supplementary Information

Supplementary Figures 1–25, Supplementary Tables 1–2 and Supplementary References

Supplementary Data 1

Cartesian coordinates of the relaxed ex situ model

Supplementary Data 2

Cartesian coordinates of the relaxed open circuit model

Supplementary Data 3

Cartesian coordinates of the –0.04 V relaxed model

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Cao, L., Luo, Q., Liu, W. et al. Identification of single-atom active sites in carbon-based cobalt catalysts during electrocatalytic hydrogen evolution. Nat Catal 2, 134–141 (2019). https://doi.org/10.1038/s41929-018-0203-5

Download citation

Further reading

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