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.

An oxygen reduction electrocatalyst based on carbon nanotube–graphene complexes

Abstract

Oxygen reduction reaction catalysts based on precious metals such as platinum or its alloys are routinely used in fuel cells because of their high activity. Carbon-supported materials containing metals such as iron or cobalt as well as nitrogen impurities have been proposed to increase scalability and reduce costs, but these alternatives usually suffer from low activity and/or gradual deactivation during use. Here, we show that few-walled carbon nanotubes, following outer wall exfoliation via oxidation and high-temperature reaction with ammonia, can act as an oxygen reduction reaction electrocatalyst in both acidic and alkaline solutions. Under a unique oxidation condition, the outer walls of the few-walled carbon nanotubes are partially unzipped, creating nanoscale sheets of graphene attached to the inner tubes. The graphene sheets contain extremely small amounts of irons originated from nanotube growth seeds, and nitrogen impurities, which facilitate the formation of catalytic sites and boost the activity of the catalyst, as revealed by atomic-scale microscopy and electron energy loss spectroscopy. Whereas the graphene sheets formed from the unzipped part of the outer wall of the nanotubes are responsible for the catalytic activity, the inner walls remain intact and retain their electrical conductivity, which facilitates charge transport during electrocatalysis.

Your institute does not have access to this article

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Figure 1: Structural and compositional characterization of carbon nanotube–graphene complexes.
Figure 2: Electrochemical characterization of the carbon nanotube–graphene ORR catalyst.
Figure 3: Characterization of the durability and methanol tolerance of the NT–G ORR catalyst.
Figure 4: Characterization of the role of iron in ORR catalysed by the NT–G material.
Figure 5: Microscopy imaging and spectroscopic mapping of iron and nitrogen atoms on carbon nanotube–graphene complexes.

References

  1. Gewirth, A. A. & Thorum, M. S. Electroreduction of dioxygen for fuel-cell applications: materials and challenges. Inorg. Chem. 49, 3557–3566 (2010).

    CAS  Article  Google Scholar 

  2. Winter, M. & Brodd, R. J. What are batteries, fuel cells, and supercapacitors? Chem. Rev. 104, 4245–4269 (2004).

    CAS  Article  Google Scholar 

  3. Gasteiger, H. A., Kocha, S. S., Sompalli, B. & Wagner, F. T. Activity benchmarks and requirements for Pt, Pt-alloy, and non-Pt oxygen reduction catalysts for PEMFCs. Appl. Catal. B 56, 9–35 (2005).

    CAS  Article  Google Scholar 

  4. Wu, J. & Yang, H. Synthesis and electrocatalytic oxygen reduction properties of truncated octahedral Pt3Ni nanoparticles. Nano Res. 4, 72–82 (2011).

    CAS  Article  Google Scholar 

  5. Lim, B., Jiang, M., Yu, T., Camargo, P. H. C. & Xia, Y. X. Nucleation and growth mechanisms for Pd–Pt bimetallic nanodendrites and their electrocatalytic properties. Nano Res. 3, 69–80 (2010).

    CAS  Article  Google Scholar 

  6. Bezerra, C. W. B. et al. A review of Fe-N/C and Co-N/C catalysts for the oxygen reduction reaction. Electrochim. Acta 53, 4937–4951 (2008).

    CAS  Article  Google Scholar 

  7. Jaouen, F. et al. Recent advances in non-precious metal catalysis for oxygen-reduction reaction in polymer electrolyte fuel cells. Energy Environ. Sci. 4, 114–130 (2011).

    CAS  Article  Google Scholar 

  8. Lefevre, M., Proietti, E., Jaouen, F. & Dodelet, J-P. Iron-based catalysts with improved oxygen reduction activity in polymer electrolyte fuel cells. Science 324, 71–74 (2009).

    CAS  Article  Google Scholar 

  9. Wu, G., More, K. L., Johnston, C. M. & Zelenay, P. High-performance electrocatalysts for oxygen reduction derived from polyaniline, iron, and cobalt. Science 332, 443–447 (2011).

    CAS  Article  Google Scholar 

  10. Pylypenko, S., Mukherjee, S., Olson, T. S. & Atanassov, P. Non-platinum oxygen reduction electrocatalysts based on pyrolyzed transition metal macrocycles. Electrochim. Acta 53, 7875–7883 (2008).

    CAS  Article  Google Scholar 

  11. Yang, J., Liu, D-J., Kariuki, N. N. & Chen, L. X. Aligned carbon nanotubes with built-in FeN4 active sites for electrocatalytic reduction of oxygen. Chem. Commun. 329–331 (2008).

  12. Xiong, W. et al. 3-D carbon nanotube structures used as high performance catalyst for oxygen reduction reaction. J. Am. Chem. Soc. 132, 15839–15841 (2010).

    CAS  Article  Google Scholar 

  13. Kundu, S. et al. Electrocatalytic activity and stability of nitrogen-containing carbon nanotubes in the oxygen reduction reaction. J. Phys. Chem. C 113, 14302–14310 (2009).

    CAS  Article  Google Scholar 

  14. Geng, D. et al. Non-noble metal oxygen reduction electrocatalysts based on carbon nanotubes with controlled nitrogen contents. J. Power Sources 196, 1795–1801 (2011).

    CAS  Article  Google Scholar 

  15. Wiggins-Camacho, J. D. & Stevenson, K. J. Mechanistic discussion of the oxygen reduction reaction at nitrogen-doped carbon nanotubes. J. Phys. Chem. C 115, 20002–20010 (2011).

    CAS  Article  Google Scholar 

  16. Nagaiah, T. C., Kundu, S., Bron, M., Muhler, M. & Schuhmann, W. Nitrogen-doped carbon nanotubes as a cathode catalyst for the oxygen reduction reaction in alkaline medium. Electrochem. Commun. 12, 338–341 (2010).

    CAS  Article  Google Scholar 

  17. Gong, K., Du, F., Xia, Z., Durstock, M. & Dai, L. Nitrogen-doped carbon nanotube arrays with high electrocatalytic activity for oxygen reduction. Science 323, 760–764 (2009).

    CAS  Article  Google Scholar 

  18. Ning, G., Liu, Y., Wei, F., Wen, Q. & Luo, G. Porous and lamella-like Fe/MgO catalysts prepared under hydrothermal conditions for high-yield synthesis of double-walled carbon nanotubes. J. Phys. Chem. C 111, 1969–1975 (2007).

    CAS  Article  Google Scholar 

  19. Kosynkin Dmitry, V. et al. Longitudinal unzipping of carbon nanotubes to form graphene nanoribbons. Nature 458, 872–876 (2009).

    CAS  Article  Google Scholar 

  20. Wang, H., Cote, R., Faubert, G., Guay, D. & Dodelet, J. P. Effect of the pre-treatment of carbon black supports on the activity of Fe-based electrocatalysts for the reduction of oxygen. J. Phys. Chem. B 103, 2042–2049 (1999).

    CAS  Article  Google Scholar 

  21. Li, X. et al. Simultaneous nitrogen doping and reduction of graphene oxide. J. Am. Chem. Soc. 131, 15939–15944 (2009).

    CAS  Article  Google Scholar 

  22. Jaouen, F., Serventi, A. M., Lefevre, M., Dodelet, J-P. & Bertrand, P. Non-noble electrocatalysts for O2 reduction: how does heat treatment affect their activity and structure? Part II. Structural changes observed by electron microscopy, Raman, and mass spectroscopy. J. Phys. Chem. C 111, 5971–5976 (2007).

    CAS  Article  Google Scholar 

  23. Wang, X. et al. N-doping of graphene through electrothermal reactions with ammonia. Science 324, 768–771 (2009).

    CAS  Article  Google Scholar 

  24. Garsany, Y., Baturina, O. A., Swider-Lyons, K. E. & Kocha, S. S. Experimental methods for quantifying the activity of platinum electrocatalysts for the oxygen reduction reaction. Anal. Chem. 82, 6321–6328 (2010).

    CAS  Article  Google Scholar 

  25. Gong, K. et al. Platinum-monolayer electrocatalysts: palladium interlayer on IrCo alloy core improves activity in oxygen-reduction reaction. J. Electroanal. Chem. 649, 232–237 (2010).

    CAS  Article  Google Scholar 

  26. Lima, F. H. B. et al. Catalytic activity-d-band center correlation for the O2 reduction reaction on platinum in alkaline solutions. J. Phys. Chem. C 111, 404–410 (2007).

    CAS  Article  Google Scholar 

  27. Meng, H., Jaouen, F., Proietti, E., Lefevre, M. & Dodelet, J-P. pH-effect on oxygen reduction activity of Fe-based electro-catalysts. Electrochem. Commun. 11, 1986–1989 (2009).

    CAS  Article  Google Scholar 

  28. Anderson, A. B. & Sidik, R. A. Oxygen electroreduction on FeII and FeIII coordinated to N4 chelates. Reversible potentials for the intermediate steps from quantum theory. J. Phys. Chem. B 108, 5031–5035 (2004).

    CAS  Article  Google Scholar 

  29. Medard, C., Lefevre, M., Dodelet, J. P., Jaouen, F. & Lindbergh, G. Oxygen reduction by Fe-based catalysts in PEM fuel cell conditions: activity and selectivity of the catalysts obtained with two Fe precursors and various carbon supports. Electrochim. Acta 51, 3202–3213 (2006).

    CAS  Article  Google Scholar 

  30. Yu, D., Zhang, Q. & Dai, L. Highly efficient metal-free growth of nitrogen-doped single-walled carbon nanotubes on plasma-etched substrates for oxygen reduction. J. Am. Chem. Soc. 132, 15127–15129 (2010).

    CAS  Article  Google Scholar 

  31. Wu, G. et al. Titanium dioxide-supported non-precious metal oxygen reduction electrocatalyst. Chem. Commun. 46, 7489–7491 (2010).

    CAS  Article  Google Scholar 

  32. Li, X., Liu, C., Xing, W. & Lu, T. Development of durable carbon black/titanium dioxide supported macrocycle catalysts for oxygen reduction reaction. J. Power Sources 193, 470–476 (2009).

    CAS  Article  Google Scholar 

  33. Esumi, K., Ishigami, M., Nakajima, A., Sawada, K. & Honda, H. Chemical treatment of carbon nanotubes. Carbon 34, 279–281 (1996).

    CAS  Article  Google Scholar 

  34. Gupta, S., Fierro, C. & Yeager, E. The effects of cyanide on the electrochemical properties of transition-metal macrocycles for oxygen reduction in alkaline-solutions. J. Electroanal. Chem. 306, 239–250 (1991).

    CAS  Article  Google Scholar 

  35. Thorum, M. S., Hankett, J. M. & Gewirth, A. A. Poisoning the oxygen reduction reaction on carbon-supported Fe and Cu electrocatalysts: evidence for metal-centered activity. J. Phys. Chem. Lett. 2, 295–298 (2011).

    CAS  Article  Google Scholar 

  36. Krivanek, O. L. et al. Atom-by-atom structural and chemical analysis by annular dark-field electron microscopy. Nature 464, 571–574 (2010).

    CAS  Article  Google Scholar 

  37. Hunt, J. A. & Williams, D. B. Electron energy-loss spectrum-imaging. Ultramicroscopy 38, 47–73 (1991).

    CAS  Article  Google Scholar 

  38. Scherson, D. A. et al. In situ and ex situ Moessbauer spectroscopy studies of iron phthalocyanine adsorbed on high surface area carbon. J. Phys. Chem. 87, 932–943 (1983).

    CAS  Article  Google Scholar 

  39. Lefevre, M., Dodelet, J. P. & Bertrand, P. Molecular oxygen reduction in PEM fuel cells: evidence for the simultaneous presence of two active sites in Fe-based catalysts. J. Phys. Chem. B 106, 8705–8713 (2002).

    CAS  Article  Google Scholar 

  40. Thomas, L. A. et al. Carboxylic acid-stabilized iron oxide nanoparticles for use in magnetic hyperthermia. J. Mater. Chem. 19, 6529–6535 (2009).

    CAS  Article  Google Scholar 

  41. Wu, C., Li, J., Dong, G. & Guan, L. Removal of ferromagnetic metals for the large-scale purification of single-walled carbon nanotubes. J. Phys. Chem. C 113, 3612–3616 (2009).

    CAS  Article  Google Scholar 

Download references

Acknowledgements

This work was supported in part by a Stinehart Grant for Energy Research at Stanford from the Stanford Precourt Institute for Energy, Intel and NCEM at Lawrence Berkeley Laboratory, which was supported by the US DOE (DE-AC02-05CH11231). W.Z. was supported by the NSF (DMR-0938330). J-C.I. was supported by Oak Ridge National Laboratory's Shared Research Equipment (ShaRE) User Facility, which is sponsored by the Office of Basic Energy Sciences, US Department of Energy. S.J.P. was supported by the Basic Energy Sciences programme of the Materials Sciences and Engineering Division of the US DOE.

Author information

Authors and Affiliations

Authors

Contributions

Y.Li and H.D. conceived the project and designed the experiments. W.Z., J-C.I. and S.J.P. conducted ADF and EELS studies. F.W. synthesized carbon nanotubes. Y.Li, H.W., L.X. and Y.Liang performed catalyst preparation, structural characterizations and electrochemical measurements. Y.Li, W.Z., H.W., L.X., Y.Liang, F.W., J-C.I., S.J.P. and H.D. analysed the data. Y.Li and H.D. co-wrote the paper. All authors discussed the results and commented on the manuscript.

Corresponding author

Correspondence to Hongjie Dai.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 2143 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Li, Y., Zhou, W., Wang, H. et al. An oxygen reduction electrocatalyst based on carbon nanotube–graphene complexes. Nature Nanotech 7, 394–400 (2012). https://doi.org/10.1038/nnano.2012.72

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nnano.2012.72

Further reading

Search

Quick links

Find nanotechnology articles, nanomaterial data and patents all in one place. Visit Nano by Nature Research