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Ta–TiOx nanoparticles as radical scavengers to improve the durability of Fe–N–C oxygen reduction catalysts

Nature Energy volume 7, pages 281–289 (2022)Cite this article

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Abstract

Highly active and durable platinum group metal-free catalysts for the oxygen reduction reaction, such as Fe–N–C materials, are needed to lower the cost of proton-exchange membrane fuel cells. However, their durability is impaired by the attack of oxidizing radicals such as ·OH and HO2· that form from incomplete reduction of O2 via H2O2. Here we demonstrate that Ta–TiOx nanoparticle additives protect Fe–N–C catalysts from such degradation via radical scavenging. The 5 nm Ta–TiOx nanoparticles were uniformly synthesized on a Ketjenblack substrate using a high-temperature pulse technique, forming the rutile TaO2 phase. We found that Ta–TiOx nanoparticles suppressed the H2O2 yield by 51% at 0.7 V in an aqueous rotating ring disk electrode test. After an accelerated durability test, a fuel cell prepared with the scavengers showed a current density decay of 3% at 0.9 ViR-free (internal resistance-compensated voltage); a fuel cell without scavengers showed 33% decay. Thus, addition of Ta–TiOx provides an active defence strategy to improve the durability of oxygen reduction reaction catalysts.

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Fig. 1: Schematic comparing the PGM-free catalyst durability in the ORR process without and with the Ta–TiOx/Ketjenblack scavengers.
Fig. 2: Morphology of the Ta–TiOx radical scavengers.
Fig. 3: The radical scavenging performance of Ta–TiOx/KB.
Fig. 4: The Fe–N–C catalyst protection and H2O2 suppression performance of the Ta–TiOx/KB scavengers.
Fig. 5: PEM fuel cell performances of the PGM-free cathode with and without Ta–TiOx/KB.
Fig. 6: DFT calculations to understand the radical scavenging performance of the Ta–TiOx/KB.

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The authors declare that all data supporting the findings of this study are available within the paper and Supplementary Information files. Source data are provided with this paper.

References

  1. Shao, M., Chang, Q., Dodelet, J. P. & Chenitz, R. Recent advances in electrocatalysts for oxygen reduction reaction. Chem. Rev. 116, 3594–3657 (2016).

    Article  Google Scholar 

  2. Wang, X. X., Swihart, M. T. & Wu, G. Achievements, challenges and perspectives on cathode catalysts in proton exchange membrane fuel cells for transportation. Nat. Catal. 2, 578–589 (2019).

    Article  Google Scholar 

  3. Li, M. et al. Ultrafine jagged platinum nanowires enable ultrahigh mass activity for the oxygen reduction reaction. Science 354, 1414–1419 (2016).

    Article  Google Scholar 

  4. Jasinski, R. A new fuel cell cathode catalyst. Nature 201, 1963–1964 (1964).

    Article  Google Scholar 

  5. Gewirth, A. A., Varnell, J. A. & Diascro, A. M. Nonprecious metal catalysts for oxygen reduction in heterogeneous aqueous systems. Chem. Rev. 118, 2313–2339 (2018).

    Article  Google Scholar 

  6. Setzler, B. P., Zhuang, Z., Wittkopf, J. A. & Yan, Y. Activity targets for nanostructured platinum-group-metal-free catalysts in hydroxide exchange membrane fuel cells. Nat. Nanotechnol. 11, 1020–1025 (2016).

    Article  Google Scholar 

  7. Zhang, H. et al. Single atomic iron catalysts for oxygen reduction in acidic media: particle size control and thermal activation. J. Am. Chem. Soc. 139, 14143–14149 (2017).

    Article  Google Scholar 

  8. 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  Google Scholar 

  9. 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  Google Scholar 

  10. Lefèvre, 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).

    Article  Google Scholar 

  11. Proietti, E. et al. Iron-based cathode catalyst with enhanced power density in polymer electrolyte membrane fuel cells. Nat. Commun. 2, 416 (2011).

    Article  Google Scholar 

  12. Zhang, G., Chenitz, R., Lefèvre, M., Sun, S. & Dodelet, J. P. Is iron involved in the lack of stability of Fe/N/C electrocatalysts used to reduce oxygen at the cathode of PEM fuel cells? Nano Energy 29, 111–125 (2016).

    Article  Google Scholar 

  13. Shao, Y., Dodelet, J. P., Wu, G. & Zelenay, P. PGM-free cathode catalysts for PEM fuel cells: a mini-review on stability challenges. Adv. Mater. 31, 1807615 (2019).

    Article  Google Scholar 

  14. Choi, C. H. et al. The Achilles’ heel of iron-based catalysts during oxygen reduction in an acidic medium. Energy Environ. Sci. 11, 3176–3182 (2018).

    Article  Google Scholar 

  15. Chenitz, R. et al. A specific demetalation of Fe–N4 catalytic sites in the micropores of NC–Ar + NH3 is at the origin of the initial activity loss of the highly active Fe/N/C catalyst used for the reduction of oxygen in PEM fuel cells. Energy Environ. Sci. 11, 365–382 (2018).

    Article  Google Scholar 

  16. Schmies, H. et al. Unravelling degradation pathways of oxide-supported Pt fuel cell nanocatalysts under in situ operating conditions. Adv. Energy Mater. 8, 1701663 (2018).

    Article  Google Scholar 

  17. Xie, X. et al. Performance enhancement and degradation mechanism identification of a single-atom Co–N–C catalyst for proton exchange membrane fuel cells. Nat. Catal. https://doi.org/10.1038/s41929-020-00546-1 (2020).

  18. Jaouen, F. O2 reduction mechanism on non-noble metal catalysts for PEM fuel cells. Part II: a porous-electrode model to predict the quantity of H2O2 detected by rotating ring-disk electrode. J. Phys. Chem. C. 113, 15433–15443 (2009).

    Article  Google Scholar 

  19. Lefèvre, M. & Dodelet, J. P. Fe-based catalysts for the reduction of oxygen in polymer electrolyte membrane fuel cell conditions: determination of the amount of peroxide released during electroreduction and its influence on the stability of the catalysts. Electrochim. Acta 48, 2749–2760 (2003).

    Article  Google Scholar 

  20. Kumar, K. et al. On the influence of oxygen on the degradation of Fe–N–C catalysts. Angew. Chem. 132, 3261–3269 (2020).

    Article  Google Scholar 

  21. Goellner, V., Armel, V., Zitolo, A., Fonda, E. & Jaouen, F. Degradation by hydrogen peroxide of metal–nitrogen–carbon catalysts for oxygen reduction. J. Electrochem. Soc. 162, H403–H414 (2015).

    Article  Google Scholar 

  22. Qiao, Z. et al. 3D porous graphitic nanocarbon for enhancing the performance and durability of Pt catalysts: a balance between graphitization and hierarchical porosity. Energy Environ. Sci. 12, 2830–2841 (2019).

    Article  Google Scholar 

  23. Gadipelli, S., Zhao, T., Shevlin, S. A. & Guo, Z. Switching effective oxygen reduction and evolution performance by controlled graphitization of a cobalt–nitrogen–carbon framework system. Energy Environ. Sci. 9, 1661–1667 (2016).

    Article  Google Scholar 

  24. Gouérec, P. et al. Dioxygen reduction electrocatalysis in acidic media: effect of peripheral ligand substitution on cobalt tetraphenylporphyrin. J. Electroanal. Chem. 398, 67–75 (1995).

    Article  Google Scholar 

  25. Gouérec, P. et al. Oxygen reduction in acid media catalysed by heat treated cobalt tetraazaannulene supported on an active charcoal: correlations between the performances after longevity tests and the active site configuration as seen by XPS and ToF-SIMS. J. Electroanal. Chem. 422, 61–75 (1997).

    Article  Google Scholar 

  26. Bezerra, C. W. B. et al. A review of heat-treatment effects on activity and stability of PEM fuel cell catalysts for oxygen reduction reaction. J. Power Sources 173, 891–908 (2007).

    Article  Google Scholar 

  27. Alves, M. C. M., Dodelet, J. P., Guay, D., Ladouceur, M. & Tourillon, G. Origin of the electrocatalytic properties for O2 reduction of some heat-treated polyacrylonitrile and phthalocyanine cobalt compounds adsorbed on carbon black as probed by electrochemistry and X-ray absorption spectroscopy. J. Phys. Chem. 96, 10898–10905 (1992).

    Article  Google Scholar 

  28. Ladouceur, M. et al. Pyrolyzed cobalt phthalocyanine as electrocatalyst for oxygen reduction. J. Electrochem. Soc. 140, 1974–1981 (2019).

    Article  Google Scholar 

  29. Kolthoff, H. M. & Medalia, A. I. The reaction between ferrous iron and peroxides. III. Reaction with cumene hydroperoxide, in aqueous solution. J. Am. Chem. Soc. 71, 3789–3792 (1949).

    Article  Google Scholar 

  30. Kramm, U. I. et al. On an easy way to prepare metal–nitrogen doped carbon with exclusive presence of MeN4-type sites active for the ORR. J. Am. Chem. Soc. 138, 635–640 (2016).

    Article  Google Scholar 

  31. Jaouen, F. & Dodelet, J. P. O2 reduction mechanism on non-noble metal catalysts for PEM fuel cells. Part I: experimental rates of O2 electroreduction, H2O2 electroreduction, and H2O2 disproportionation. J. Phys. Chem. C. 113, 15422–15432 (2009).

    Article  Google Scholar 

  32. Xie, H. et al. High-temperature pulse method for nanoparticle redispersion. J. Am. Chem. Soc. 142, 17364–17371 (2020).

    Article  Google Scholar 

  33. Syono, Y., Kikuchi, M., Goto, T. & Fukuoka, K. Formation of rutile-type Ta(IV)O2 by shock reduction and cation-deficient Ta0.8O2 by subsequent oxidation. J. Solid State Chem. 50, 133–137 (1983).

    Article  Google Scholar 

  34. Edgecomb, J. et al. Mapping localized peroxyl radical generation on a PEM fuel cell catalyst using integrated scanning electrochemical cell microspectroscopy. Front. Chem. 8, 572563 (2020).

    Article  Google Scholar 

  35. Prabhakaran, V., Arges, C. G. & Ramani, V. Investigation of polymer electrolyte membrane chemical degradation and degradation mitigation using in situ fluorescence spectroscopy. Proc. Natl Acad. Sci. USA 109, 1029–1034 (2012).

    Article  Google Scholar 

  36. Matuszak, Z., Reszka, K. J. & Chignell, C. F. Reaction of melatonin and related indoles with hydroxyl radicals: EPR and spin trapping investigations. Free Radic. Biol. Med. 23, 367–372 (1997).

    Article  Google Scholar 

  37. Plauck, A., Stangland, E. E., Dumesic, J. A. & Mavrikakis, M. Active sites and mechanisms for H2O2 decomposition over Pd catalysts. Proc. Natl Acad. Sci. USA 113, E1973–E1982 (2016).

    Article  Google Scholar 

  38. Laursen, A. B., Man, I. C., Trinhammer, O. L., Rossmeisl, J. & Dahl, S. The Sabatier principle illustrated by catalytic H2O2 decomposition on metal surfaces. J. Chem. Educ. 88, 1711–1715 (2011).

    Article  Google Scholar 

  39. Balbuena, P. B., Calvo, S. R., Lamas, E. J., Salazar, P. F. & Seminario, J. M. Adsorption and dissociation of H2O2 on Pt and Pt-alloy clusters and surfaces. J. Phys. Chem. B 110, 17452–17459 (2006).

    Article  Google Scholar 

  40. Poole, C. P. Electron Spin Resonance: A Comprehensive Treatise on Experimental Techniques 2nd edn, (Wiley, 1983).

  41. Lee, Y.-K., Whittaker, M. M. & Whittaker, J. W. The electronic structure of the Cys-Tyrúÿfree radical in galactose oxidase determined by EPR spectroscopy. Biochemistry 47, 6637–6649 (2008).

    Article  Google Scholar 

  42. Kresse, G. & Furthmüller, J. Bayesian optimization for calibrating and selecting hybrid-density functional models. Phys. Rev. B 54, 11169–11186 (1996).

    Article  Google Scholar 

  43. Kresse, G. & Furthmüller, J. Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set. Comput. Mater. Sci. 6, 15–50 (1996).

    Article  Google Scholar 

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

    Article  Google Scholar 

  45. Blöchl, P. E. Projector augmented-wave method. Phys. Rev. B 50, 17953 (1994).

    Article  Google Scholar 

  46. Lu, Z. et al. High-efficiency oxygen reduction to hydrogen peroxide catalysed by oxidized carbon materials. Nat. Catal. 1, 156–162 (2018).

    Article  Google Scholar 

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

    Article  Google Scholar 

Download references

Acknowledgements

L.H., Y.S., X.X. and H.X. acknowledge support from the US Department of Energy, Office of Energy Efficiency and Renewable Energy and Hydrogen and Fuel Cell Technologies Office through the Electrocatalysis consortium (ElectroCat) and from DOE programme managers D. Papageorgopoulos, S. Thompson, D. Peterson and G. Kleen. R.S.-Y. acknowledges financial support from National Science Foundation DMR-1809439. D.J. acknowledges support from the National Science Foundation CHE-2102191. G.H. acknowledges the financial support from the Queens College, City University of New York. The authors acknowledge the support of the Maryland Nanocenter, its Surface Analysis Center and AIMLab. The views and opinions of the authors expressed herein do not necessarily state or reflect those of the US government or any agency thereof. Neither the US government nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness or usefulness of any information, apparatus, product or process disclosed, or represents that its use would not infringe privately owned rights.

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  1. These authors contributed equally: Hua Xie, Xiaohong Xie.

Authors and Affiliations

  1. Department of Materials Science and Engineering, University of Maryland, College Park, MD, USA

    Hua Xie, Lorelis Gonzalez-Lopez, Min Hong, Meiling Wu, Mohamad I. Al-Sheikhly & Liangbing Hu

  2. Pacific Northwest National Laboratory, Richland, WA, USA

    Xiaohong Xie, Venkateshkumar Prabhakaran & Yuyan Shao

  3. Department of Chemistry and Biochemistry, Queens College of the City University of New York, Queens, NY, USA

    Guoxiang Hu

  4. Center for Solar Energy and Energy Storage and Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, USA

    Sulay Saha & Vijay Ramani

  5. Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, IL, USA

    Abhijit H. Phakatkar & Reza Shahbazian-Yassar

  6. Department of Chemistry, University of California, Riverside, CA, USA

    De-en Jiang

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Contributions

L.H. and Y.S. co-supervised the research. L.H., Y.S., V.P. and H.X. conceived the concept. H.X., X.X., Y.S. and L.H. designed the experiment. H.X. and X.X. carried out the experimental works including syntheses and electrochemical measurements. H.X., M.H., M.W. and A.H.P. carried out the characterization of materials. H.X., L.G.-L. and M.I.A.-S. carried out the EPR test. V.P. carried out the fluorescence test. S.S. and V.R. conducted the fuel cell test. G.H. and D.J. carried out the calculation analysis. H.X. and L.H. wrote the paper. G.H, X.X., R.S.-Y. and Y.S. revised the paper. All authors contributed to the discussion of the manuscript.

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Correspondence to Guoxiang Hu, Reza Shahbazian-Yassar, Yuyan Shao or Liangbing Hu.

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Nature Energy thanks Frédéric Jaouen, Ulrike Kramm and Samira Siahrostami for their contribution to the peer review of this work.

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Xie, H., Xie, X., Hu, G. et al. Ta–TiOx nanoparticles as radical scavengers to improve the durability of Fe–N–C oxygen reduction catalysts. Nat Energy 7, 281–289 (2022). https://doi.org/10.1038/s41560-022-00988-w

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