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.

Lattice-strain control of the activity in dealloyed core–shell fuel cell catalysts

Abstract

Electrocatalysis will play a key role in future energy conversion and storage technologies, such as water electrolysers, fuel cells and metal–air batteries. Molecular interactions between chemical reactants and the catalytic surface control the activity and efficiency, and hence need to be optimized; however, generalized experimental strategies to do so are scarce. Here we show how lattice strain can be used experimentally to tune the catalytic activity of dealloyed bimetallic nanoparticles for the oxygen-reduction reaction, a key barrier to the application of fuel cells and metal–air batteries. We demonstrate the core–shell structure of the catalyst and clarify the mechanistic origin of its activity. The platinum-rich shell exhibits compressive strain, which results in a shift of the electronic band structure of platinum and weakening chemisorption of oxygenated species. We combine synthesis, measurements and an understanding of strain from theory to generate a reactivity–strain relationship that provides guidelines for tuning electrocatalytic activity.

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

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Figure 1: Elemental maps and line profiles of Pt–Cu bimetallic nanoparticle precursors and dealloyed active catalysts.
Figure 2: HAADF-STEM images of Pt–Cu bimetallic nanoparticle precursors and dealloyed active catalysts.
Figure 3: AXRD-based structural and phase-composition analysis of Pt–Cu bimetallic nanoparticle precursors and dealloyed nanoparticle catalysts.
Figure 4: A simple structural two-phase core-shell model for the dealloyed nanoparticles and evaluation of their lattice parameters.
Figure 5: Surface-science XAS and XES studies of single-crystal model systems that mimic dealloyed bimetallic core–shell structures.
Figure 6: Experimental and predicted relationships between electrocatalytic ORR activity and lattice strain.

References

  1. Stonehart, P. Development of alloy electrocatalysts for phosphoric acid fuel cells (PAFC). Appl. Electrochem. 22, 995–1001 (1992).

    CAS  Article  Google Scholar 

  2. Mukerjee, S. & Srinivasan, S. in Handbook of Fuel Cells—Fundamentals, Technology and Applications Vol. 2. (eds Vielstich, W., Gasteiger, H. A. & Lamm, A.) 502–519 (John Wiley, 2003).

    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. Ertl, G., Knözinger, H., Schueth, F. & Weitkamp, J. Handbook of Heterogeneous Catalysis (Wiley-VCH, 2008).

    Book  Google Scholar 

  5. Somorjai, G. A. Introduction to Surface Chemistry and Catalysis (Wiley, 1994).

    Google Scholar 

  6. Sinfelt, J. H. Bimetallic Catalysts: Discoveries, Concepts, and Applications (Wiley, 1983).

    Google Scholar 

  7. Maroun, F., Ozanam, F., Magnussen, O. M. & Behm, R. J. The role of atomic ensembles in the reactivity of bimetallic electrocatalysts. Science 293, 1811–1814 (2001).

    CAS  Article  Google Scholar 

  8. Rodriguez, J. A. & Goodman, D. W. The nature of the metal–metal bond in bimetallic surfaces. Science 257, 897–903 (1992).

    CAS  Article  Google Scholar 

  9. Rodriguez, J. A. Physical and chemical properties of bimetallic surfaces. Surf. Sci. Rep. 24, 223–287 (1996).

    CAS  Article  Google Scholar 

  10. Greeley, J., Norskov, J. K. & Mavrikakis, M. Electronic structure and catalysis on metal surfaces. Annu. Rev. Phys. Chem. 53, 319–348 (2002).

    CAS  Article  Google Scholar 

  11. Hammer, B. & Nørskov, J. K. Electronic factors determining the reactivity of metal surfaces. Surf. Sci. 343, 211–220 (1995).

    CAS  Article  Google Scholar 

  12. Ruban, A., Hammer, B., Stoltze, P., Skriver, H. L. & Nørskov, J. K. Surface electronic structure and reactivity of transition and noble metals. J. Mol. Catal. A 115, 421–429 (1997).

    CAS  Article  Google Scholar 

  13. Chen, S. et al. Enhanced activity for oxygen reduction reaction on Pt3Co nanoparticles: direct evidence of percolated and sandwich segregation structures. J. Am. Chem. Soc. 130, 13818–13819 (2008).

    CAS  Article  Google Scholar 

  14. Chen, S. et al. Origin of oxygen reduction reaction activity on ‘Pt3Co’ nanoparticles: atomically resolved chemical compositions and structures. J. Phys Chem. C 113, 1109–1125 (2009).

    CAS  Article  Google Scholar 

  15. Chen, M., Kumar, D., Yi, C.-W. & Goodman, D. W. The promotional effect of gold in catalysis by palladium–gold. Science 310, 291–293 (2005).

    CAS  Article  Google Scholar 

  16. Mavrikakis, M., Hammer, B. & Norskov, J. K. Effect of strain on the reactivity of metal surfaces. Phys. Rev. Lett. 81, 2819–2822 (1998).

    Article  Google Scholar 

  17. Stamenkovic, V. R. et al. Improved oxygen reduction activity on Pt3Ni(111) via increased surface site availability. Science 315, 493–497 (2007).

    CAS  Article  Google Scholar 

  18. Stamenkovic, V. et al. Changing the activity of electrocatalysts for oxygen reduction by tuning the surface electronic structure. Angew. Chem. Int. Ed. 45, 2897–2901 (2006).

    CAS  Article  Google Scholar 

  19. Kibler, L. A., El-Aziz, A. M., Hoyer, R. & Kolb, D. M. Tuning reaction rates by lateral strain in a palladium monolayer. Angew. Chem. Int. Ed. 44, 2080–2084 (2005).

    CAS  Article  Google Scholar 

  20. Zhang, J., Vukmiovic, M. B., Xu, Y., Mavrikakis, M. & Adzic, R. R. Controlling the catalytic activity of platinum-monolayer electrocatalysts for oxygen reduction with different substrates. Angew. Chem. Int. Ed. 44, 2132 (2005).

    CAS  Article  Google Scholar 

  21. Oppenheim, I. C., Trevor, D. J., Chidsey, C. E. D., Trevor, P. L. & Sieradzki, K. In situ scanning tunneling microscopy of corrosion of silver–gold alloys. Science 254, 687–689 (1991).

    CAS  Article  Google Scholar 

  22. Erlebacher, J., Aziz, M. J., Karma, A., Dimitrov, N. & Sieradzki, K. Evolution of nanoporosity in dealloying. Nature 410, 450–453 (2001).

    CAS  Article  Google Scholar 

  23. Renner, F. U. et al. Initial corrosion observed on the atomic scale. Nature 430, 707–710 (2006).

    Article  Google Scholar 

  24. Srivastava, R., Mani, P., Hahn, N. & Strasser, P. Efficient oxygen reduction fuel cell electrocatalysis on voltammetrically de-alloyed Pt–Cu–Co nanoparticles. Angew. Chem. Int. Ed. 46, 8988–8991 (2007).

    Article  Google Scholar 

  25. Koh, S. & Strasser, P. Electrocatalysis on bimetallic surfaces: modifying catalytic reactivity for oxygen reduction by voltammetric surface de-alloying. J. Am. Chem. Soc. 129, 12624–12625 (2007).

    CAS  Article  Google Scholar 

  26. Strasser, P. in Handbook of Fuel Cells: Advances in Electrocatalysis, Materials, Diagnostics and Durability Vol. 5 & 6. (eds Vielstich, W., Gasteiger, H. A. & Yokokawa, H.) 30–47 (Wiley, 2009).

    Google Scholar 

  27. Strasser, P., Koh, S. & Greeley, J. Voltammetric surface dealloying of Pt bimetallic nanoparticles: an experimental and DFT computational analysis. Phys. Chem. Chem. Phys. 10, 3670–3683 (2008).

    CAS  Article  Google Scholar 

  28. Koh, S., Hahn, N., Yu, C. & Strasser, P. Effects of compositions and annealing conditions on the catalytic activities of Pt–Cu Nanoparticle electrocatalysts for PEMFC. J. Electrochem. Soc. 155, B1281–B1288 (2008).

    CAS  Article  Google Scholar 

  29. Vielstich, W., Lamm, A. & Gasteiger, H. (eds) Handbook of Fuel Cells—Fundamentals, Technology, and Applications (Wiley, 2003).

    Google Scholar 

  30. Janik, M. J., Taylor, C. D. & Neurock, M. First-principles analysis of the initial electroreduction steps of oxygen over Pt(111). J. Electrochem. Soc. 156, B126–B135 (2009).

    CAS  Article  Google Scholar 

  31. Subramanian, P. R. & Laughlin, D. E. in Binary Alloy Phase Diagrams 2nd edn, Vol. 2 (ed. Massalski, T. B.) 1460–1462 (ASM International, 1990).

    Google Scholar 

  32. Wang, J. X. et al. Oxygen reduction on well defined core shell nanocatalysts: particle size, facet and Pt Shell thickness effects. J. Am. Chem. Soc. 131, 17298–17302 (2009).

    CAS  Article  Google Scholar 

  33. Yu, C., Koh, S., Leisch, J., Toney, M. T. & Strasser, P. Size and composition distribution dynamics of alloy nanoparticle electrocatalysts probed by anomalous small angle X ray scattering (ASAXS). Faraday Discuss. 140, 283–296 (2008).

    CAS  Article  Google Scholar 

  34. Cullity, B. D. & Stock, S. R. Elements of X ray Diffraction 3rd edn (Prentice Hall, 2001).

    Google Scholar 

  35. Pecharsky, V. & Zavalij, P. Y. Fundamentals of Powder Diffraction and Structural Characterization of Materials (Springer, 2003).

    Google Scholar 

  36. DeGraef, M. & McHenry, M. E. Structure of Materials: An Introduction to Crystallography, Diffraction, and Symmetry (Cambridge Univ. Press, 2007).

    Google Scholar 

  37. Klimenkov, M. et al. The structure of Pt-aggregates on a supported thin aluminum oxide film in comparison with unsupported alumina: a transmission electron microscopy study. Surf. Sci. 391, 27–36 (1997).

    CAS  Article  Google Scholar 

  38. Cammarata, R. C. Surface and interface stress effects in thin films. Prog. Surf. Sci. 46, 1–38 (1994).

    CAS  Article  Google Scholar 

  39. Hammer, B. & Nørskov, J. K. Why gold is the noblest of all metals. Nature 376, 238–240 (1995).

    CAS  Article  Google Scholar 

  40. Nilsson, A. et al. The electronic structure effect in heterogeneous catalysis. Catal. Lett. 100, 111–114 (2005).

    CAS  Article  Google Scholar 

  41. Nilsson, A., Pettersson, L. G. M. & Nørskov, J. K. Chemical Bonding at Surfaces and Interfaces (Elsevier, 2008).

    Google Scholar 

  42. Fusy, J., Meneaucourt, J., Alnot, M., Huguet, C. & Ehrhardt, J. J. Growth and reactivity of evaporated platinum films on Cu(111): a study by AES, RHEED and adsorption of carbon monoxide and xenon. Appl. Surf. Sci. 93, 211–220 (1996).

    CAS  Article  Google Scholar 

  43. Bligaard, T. & Nørskov, J. K. in Chemical Bonding at Surfaces and Interfaces (eds Nilsson, A., Pettersson, L. G. M. & Nørskov, J. K.) Ch. 4 (Elsevier, 2008).

    Google Scholar 

  44. Lischka, M., Mosch, C. & Gross, A. Tuning catalytic properties of bimetallic surfaces: oxygen adsorption on pseudomorphic Pt/Ru overlayers. Electrochim. Acta 52, 2219–2228 (2007).

    CAS  Article  Google Scholar 

  45. Norskov, J. K. et al. Origin of the overpotential for oxygen reduction at a fuel-cell cathode. J. Phys. Chem. B 108, 17886–17892 (2004).

    CAS  Article  Google Scholar 

  46. Schlapka, A., Lischka, M., Groß, A., Käsberger, U. & Jakob, P. Surface strain versus substrate interaction in heteroepitaxial metal layers: Pt on Ru(0001). Phys. Rev. Lett. 91, 016101 (2003).

    CAS  Article  Google Scholar 

  47. Mani, P., Srivastava, S. & Strasser, P. Dealloyed Pt–Cu Core–Shell Nanoparticle electrocatalysts for use in PEM fuel cell cathodes. J. Phys. Chem. C 112, 2770–2778 (2008).

    CAS  Article  Google Scholar 

  48. Hammer, B., Hansen, L. B. & Nørskov, J. K. Improved adsorption energetics within density-functional theory using revised Perdew–Burke–Ernzerhof functionals. Phys. Rev. B 59, 7413–7421 (1999).

    Article  Google Scholar 

  49. Yeh, J. J. & Lindau, I. Atomic Data and Nuclear Data Tables 32, 1–155 (1985).

    CAS  Article  Google Scholar 

Download references

Acknowledgements

This project was supported by the Department of Energy, Office of Basic Energy Sciences, under the auspices of the President's Hydrogen Fuel Initiative. Acknowledgment is also made to the National Science Foundation (grant #729722) for partial support of this research. P.S. acknowledges support from the Cluster of Excellence in Catalysis (UNICAT) funded by the German National Science Foundation (Deutsche Forschungsgemeinschaft) and managed by the Technical University Berlin, Germany. Portions of this research were carried out at the Stanford Synchrotron Radiation Lightsource, a national user facility operated by Stanford University on behalf of the US Department of Energy, Office of Basic Energy Sciences. Use of the Center for Nanoscale Materials was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract No. DE-AC02-06CH11357. We acknowledge computer time at the Laboratory Computing Resource Center (LCRC) at Argonne National Laboratory, the National Energy Research Scientific Computing Center (NERSC) and the EMSL, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory. Microscopy research supported by ORNL's SHaRE User Program, which is sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, US Department of Energy. The authors thank L. Pettersson for reading the manuscript.

Author information

Authors and Affiliations

Authors

Contributions

P.S., M.F.T., J.G. and A.N. designed the research and co-wrote the paper, S.K., T.A., K.M., C.Y., Z.L., S.K., D.N. and H.O. performed the experiments and analysed the data, and J.G. performed the theoretical calculations.

Corresponding author

Correspondence to Peter Strasser.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Strasser, P., Koh, S., Anniyev, T. et al. Lattice-strain control of the activity in dealloyed core–shell fuel cell catalysts. Nature Chem 2, 454–460 (2010). https://doi.org/10.1038/nchem.623

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nchem.623

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