Skip to main content
SpringerLink
Log in

Rational design of Fe-N-C electrocatalysts for oxygen reduction reaction: From nanoparticles to single atoms

  • Review Article
  • Published:
Nano Research Aims and scope Submit manuscript

Abstract

As an alternative energy, hydrogen can be converted into electrical energy via direct electrochemical conversion in fuel cells. One important drawback of full cells is the sluggish oxygen reduction reaction (ORR) promoted by the high-loading of platinum-group-metal (PGM) electrocatalysts. Fe-N-C family has been received extensive attention because of its low cost, long service life and high oxygen reduction reaction activity in recent years. In order to further enhance the ORR activity, the synthesis method, morphology regulation and catalytic mechanism of the active sites in Fe-N-C catalysts are investigated. This paper reviews the research progress of Fe-N-C from nanoparticles to single atoms. The structure-activity relationship and catalytic mechanism of the catalyst are studied and discussed, which provide a guidance for rational design of the catalyst, so as to promote the more reasonable design of Fe-N-C materials.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Chu, S.; Majumdar, A. Opportunities and challenges for a sustainable energy future. Nature2012, 488, 294–303.

    Article  CAS  Google Scholar 

  2. Talaie, E.; Bonnick, P.; Sun, X. Q.; Pang, Q.; Liang, X.; Nazar, L. F. Methods and protocols for electrochemical energy storage materials research. Chem. Mater.2017, 29, 90–105.

    Article  CAS  Google Scholar 

  3. Seh, Z. W.; Kibsgaard, J.; Dickens, C. F.; Chorkendorff, I.; Nørskov, J. K.; Jaramillo, T. F. Combining theory and experiment in electrocatalysis: Insights into materials design. Science2017, 355, eaad4998.

    Article  Google Scholar 

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

    Article  CAS  Google Scholar 

  5. Xiao, M. L.; Zhu, J. B.; Li, G. R.; Li, N.; Li, S.; Cano, Z. P.; Ma, L.; Cui, P. X.; Xu, P.; Jiang, G. P. et al. Rücktitelbild: A single-atom iridium heterogeneous catalyst in oxygen reduction reaction (Angew. Chem. 28/2019). Angew. Chem., Int. Ed.2019, 131, 9750.

    Article  Google Scholar 

  6. Wang, Y. C.; Lai, Y. J.; Song, L.; Zhou, Z. Y.; Liu, J. G.; Wang, Q.; Yang, X. D.; Chen, C.; Shi, W.; Zheng, Y. P. et al. S-doping of an Fe/N/C ORR catalyst for polymer electrolyte membrane fuel cells with high power density. Angew. Chem., Int. Ed.2015, 127, 10045–10048.

    Article  Google Scholar 

  7. Wang, Y. J.; Zhao, N. N.; Fang, B. Z.; Li, H.; Bi, X. T.; Wang, H. J. Carbon-supported Pt-based alloy electrocatalysts for the oxygen reduction reaction in polymer electrolyte membrane fuel cells: Particle size, shape, and composition manipulation and their impact to activity. Chem. Rev.2015, 115, 3433–3467.

    Article  CAS  Google Scholar 

  8. Escaño, M. C. S. First-principles calculations of the dissolution and coalescence properties of Pt nanoparticle ORR catalysts: The effect of nanoparticle shape. Nano Res.2015, 8, 1689–1697.

    Article  Google Scholar 

  9. Xu, J.; Lai, S. H.; Qi, D. F.; Hu, M.; Peng, X. Y.; Liu, Y. F.; Liu, W.; Hu, G. Z.; Xu, H.; Li, F. et al. Atomic Fe-Zn dual-metal sites for high-efficiency pH-universal oxygen reduction catalysis. Nano Res.2021, 14, 1374–1381.

    Article  CAS  Google Scholar 

  10. Ye, W.; Sun, Z. T.; Wang, C. M.; Ye, M. S.; Ren, C. H.; Long, R.; Zheng, X. S.; Zhu, J. F.; Wu, X. J.; Xiong, Y. J. Enhanced O2 reduction on atomically thin Pt-based nanoshells by integrating surface facet, interfacial electronic, and substrate stabilization effects. Nano Res.2018, 11, 3313–3326.

    Article  CAS  Google Scholar 

  11. Wang, H. W.; Luo, W. J.; Zhu, L. J.; Zhao, Z. P.; Bin, E.; Tu, W. Z.; Ke, X. X.; Sui, M. L.; Chen, C. F.; Chen, Q. et al. Synergistically enhanced oxygen reduction electrocatalysis by subsurface atoms in ternary PdCuNi alloy catalysts. Adv. Funct. Mater.2018, 28, 1707219.

    Article  Google Scholar 

  12. Zhao, Z. P.; Chen, C. L.; Liu, Z. Y.; Huang, J.; Wu, M. H.; Liu, H. T.; Li, Y. J.; Huang, Y. Pt-based nanocrystal for electrocatalytic oxygen reduction. Adv. Mater.2019, 31, 1808115.

    Article  Google Scholar 

  13. Liang, H. F.; Meng, F.; Cabán-Acevedo, M.; Li, L. S.; Forticaux, A.; Xiu, L. C.; Wang, Z. C.; Jin, S. Hydrothermal continuous flow synthesis and exfoliation of NiCo layered double hydroxide nanosheets for enhanced oxygen evolution catalysis. Nano Lett.2015, 15, 1421–1427.

    Article  CAS  Google Scholar 

  14. Deng, X. H.; Tüysüz, H. Cobalt-oxide-based materials as water oxidation catalyst: Recent progress and challenges. ACS Catal.2014, 4, 3701–3714.

    Article  CAS  Google Scholar 

  15. Xue, Y. R.; Fang, J. J.; Wang, X. D.; Xu, Z. Y.; Zhang, Y. F.; Lv, Q. Q.; Liu, M. Y.; Zhu, W.; Zhuang, Z. B. Sulfate-functionalized RuFeOx as highly efficient oxygen evolution reaction electrocatalyst in acid. Adv. Funct. Mater.2021, 31, 2101405.

    Article  CAS  Google Scholar 

  16. Huang, J. Z.; Sheng, H. Y.; Ross, R. D.; Han, J. C.; Wang, X. J.; Song, B.; Jin, S. Modifying redox properties and local bonding of Co3O4 by CeO2 enhances oxygen evolution catalysis in acid. Nat. Commun.2021, 12, 3036.

    Article  CAS  Google Scholar 

  17. Zahran, Z. N.; Mohamed, E. A.; Tsubonouchi, Y.; Ishizaki, M.; Togashi, T.; Kurihara, M.; Saito, K.; Yui, T.; Yagi, M. Electrocatalytic water splitting with unprecedentedly low overpotentials by nickel sulfide nanowires stuffed into carbon nitride scabbards. Energy Environ. Sci., in press, DOI: https://doi.org/10.1039/D1EE00509J.

  18. Li, S.; Chen, B. B.; Wang, Y.; Ye, M. Y.; van Aken, P. A.; Cheng, C.; Thomas, A. Oxygen-evolving catalytic atoms on metal carbides. Nat. Mater., in press, DOI: https://doi.org/10.1038/s41563-021-01006-2.

  19. Bahadori, S. R.; Hart, R.; Hao, Y. W. Synthesis of cobalt, palladium, and rhenium nanoparticles. Tungsten2020, 2, 261–288.

    Article  Google Scholar 

  20. Aftab, U.; Tahira, A.; Mazzaro, R.; Morandi, V.; Abro, M. I.; Baloch, M. M.; Syed, J. A.; Nafady, A.; Ibupoto, Z. H. Facile NiCo2S4/C nanocomposite: An efficient material for water oxidation. Tungsten2020, 2, 403–410.

    Article  Google Scholar 

  21. Karakaya, C.; Solati, N.; Savacı, U.; Keleş, E.; Turan, S.; Çelebi, S.; Kaya, S. Mesoporous thin-film NiS2 as an idealized pre- electrocatalyst for a hydrogen evolution reaction. ACS Catal.2020, 10, 15114–15122.

    Article  CAS  Google Scholar 

  22. Zhou, Y. Q.; Zhang, L. F.; Suo, H. L.; Hua, W. B.; Indris, S.; Lei, Y. J.; Lai, W. H.; Wang, Y. X.; Hu, Z. P.; Liu, H. K. et al. Atomic cobalt vacancy-cluster enabling optimized electronic structure for efficient water splitting. Adv. Funct. Mater.2021, 31, 2101797.

    Article  CAS  Google Scholar 

  23. Li, Y. K.; Zhang, G.; Huang, H.; Lu, W. T.; Cao, F. F.; Shao, Z. G. Ni17W3-W interconnected hybrid prepared by atmosphere-and thermal-induced phase separation for efficient electrocatalysis of alkaline hydrogen evolution. Small2020, 16, 2005184.

    Article  CAS  Google Scholar 

  24. Lin, F.; Dong, Z. H.; Yao, Y. H.; Yang, L.; Fang, F.; Jiao, L. F. Electrocatalytic hydrogen evolution of ultrathin Co-Mo5N6 heterojunction with interfacial electron redistribution. Adv. Energy Mater.2020, 10, 2002176.

    Article  CAS  Google Scholar 

  25. Zhang, G. W.; Wang, B.; Li, L.; Yang, S. C. Phosphorus and yttrium codoped Co(OH)F nanoarray as highly efficient and bifunctional electrocatalysts for overall water splitting. Small2019, 15, 1904105.

    Article  CAS  Google Scholar 

  26. Zhang, T. Y.; Han, X.; Yang, H. B.; Han, A. J.; Hu, E. Y.; Li, Y. P.; Yang, X. Q.; Wang, L.; Liu, J. F.; Liu, B. Atomically dispersed Nickel(I) on an alloy-encapsulated nitrogen-doped carbon nanotube array for high-performance electrochemical CO2 reduction reaction. Angew. Chem., Int. Ed.2020, 59, 12055–12061.

    Article  CAS  Google Scholar 

  27. Kim, C.; Cho, K. M.; Park, K.; Kim, J. Y.; Yun, G. T.; Toma, F. M.; Gereige, I.; Jung, H. T. Cu/Cu2O interconnected porous aerogel catalyst for highly productive electrosynthesis of ethanol from CO2. Adv. Funct. Mater.2021, 31, 2102142.

    Article  CAS  Google Scholar 

  28. Gong, K. P.; Du, F.; Xia, Z. H.; Durstock, M.; Dai, L. M. Nitrogen-doped carbon nanotube arrays with high electrocatalytic activity for oxygen reduction. Science2009, 323, 760–764.

    Article  CAS  Google Scholar 

  29. Zhang, J. Q.; Sun, B.; Zhao, Y. F.; Tkacheva, A.; Liu, Z. J.; Yan, K.; Guo, X.; McDonagh, A. M.; Shanmukaraj, D.; Wang, C. Y. et al. A versatile functionalized ionic liquid to boost the solution-mediated performances of lithium-oxygen batteries. Nat. Commun.2019, 10, 602.

    Article  CAS  Google Scholar 

  30. Mistry, H.; Varela, A. S.; Kühl, S.; Strasser, P.; Cuenya, B. R. Nanostructured electrocatalysts with tunable activity and selectivity. Nat. Rev. Mater.2016, 1, 16009.

    Article  CAS  Google Scholar 

  31. Lefèvre, M.; Proietti, E.; Jaouen, F.; Dodelet, J. P. Iron-based catalysts with improved oxygen reduction activity in polymer electrolyte fuel cells. Science2009, 324, 71–74.

    Article  Google Scholar 

  32. Debe, M. K. Electrocatalyst approaches and challenges for automotive fuel cells. Nature2012, 486, 43–51.

    Article  CAS  Google Scholar 

  33. Shao, M. H.; Chang, Q. W.; Dodelet, J. P.; Chenitz, R. Recent advances in electrocatalysts for oxygen reduction reaction. Chem. Rev.2016, 116, 3594–3657.

    Article  CAS  Google Scholar 

  34. Jaouen, F.; Proietti, E.; Lefèvre, M.; Chenitz, R.; Dodelet, J. P.; Wu, G.; Chung, H. T.; Johnston, C. M.; Zelenay, P. Recent advances in non-precious metal catalysis for oxygen-reduction reaction in polymer electrolyte fuelcells. Energy Environ. Sci.2011, 4, 114–130.

    Article  CAS  Google Scholar 

  35. Armel, V.; Hindocha, S.; Salles, F.; Bennett, S.; Jones, D.; Jaouen, F. Structural descriptors of zeolitic-imidazolate frameworks are keys to the activity of Fe-N-C catalysts. J. Am. Chem. Soc.2017, 139, 453–464.

    Article  CAS  Google Scholar 

  36. Jiang, Y.; Deng, Y. P.; Liang, R. L.; Fu, J.; Luo, D.; Liu, G. H.; Li, J. D.; Zhang, Z.; Hu, Y. F.; Chen, Z. W. Multidimensional ordered bifunctional air electrode enables flash reactants shuttling for high-energy flexible Zn-air batteries. Adv. Energy Mater.2019, 9, 1900911.

    Article  Google Scholar 

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

    Article  CAS  Google Scholar 

  38. Sun, J. Q.; Lowe, S. E.; Zhang, L. J.; Wang, Y. Z.; Pang, K. L.; Wang, Y.; Zhong, Y. L.; Liu, P. R.; Zhao, K.; Tang, Z. Y. et al. Ultrathin nitrogen-doped holey carbon@graphene bifunctional electrocatalyst for oxygen reduction and evolution reactions in alkaline and acidic media. Angew. Chem., Int. Ed.2018, 57, 16511–16515.

    Article  CAS  Google Scholar 

  39. Wang, B. W.; Wang, X. X.; Zou, J. X.; Yan, Y. C.; Xie, S. H.; Hu, G. Z.; Li, Y. G.; Dong, A. G. Simple-cubic carbon frameworks with atomically dispersed iron dopants toward high-efficiency oxygen reduction. Nano Lett.2017, 17, 2003–2009.

    Article  CAS  Google Scholar 

  40. Nie, Y.; Li, L.; Wei, Z. D. Recent advancements in Pt and Pt-free catalysts for oxygen reduction reaction. Chem. Soc. Rev.2015, 44, 2168–2201.

    Article  CAS  Google Scholar 

  41. Pegis, M. L.; Wise, C. F.; Martin, D. J.; Mayer, J. M. Oxygen reduction by homogeneous molecular catalysts and electrocatalysts. Chem. Rev.2018, 118, 2340–2391.

    Article  CAS  Google Scholar 

  42. Masa, J.; Xia, W.; Muhler, M.; Schuhmann, W. On the role of metals in nitrogen-doped carbon electrocatalysts for oxygen reduction. Angew. Chem., Int. Ed.2015, 54, 10102–10120.

    Article  CAS  Google Scholar 

  43. Chen, C.; Kang, Y. J.; Huo, Z. Y.; Zhu, Z. W.; Huang, W. Y.; Xin, H. L.; Snyder, J. D.; Li, D. G.; Herron, J. A.; Mavrikakis, M. et al. Highly crystalline multimetallic nanoframes with three-dimensional electrocatalytic surfaces. Science2014, 343, 1339–1343.

    Article  CAS  Google Scholar 

  44. Wang, Y.; Wang, D. S.; Li, Y. D. A fundamental comprehension and recent progress in advanced Pt-based ORR nanocatalysts. SmartMat2021, 2, 56–75.

    Article  Google Scholar 

  45. Li, F.; Han, G. F.; Noh, H. J.; Kim, S. J.; Lu, Y. L.; Jeong, H. Y.; Fu, Z. P.; Baek, J. B. Boosting oxygen reduction catalysis with abundant copper single atom active sites. Energy Environ. Sci.2018, 11, 2263–2269.

    Article  CAS  Google Scholar 

  46. Ling, T.; Zhang, T.; Ge, B. H.; Han, L. L.; Zheng, L. R.; Lin, F.; Xu, Z. R.; Hu, W. B.; Du, X. W.; Davey, K. et al. Electrocatalysis: Well-dispersed nickel- and zinc-tailored electronic structure of a transition metal oxide for highly active alkaline hydrogen evolution reaction (Adv. Mater. 16/2019). Adv. Mater.2019, 31, 1970113.

    Article  Google Scholar 

  47. Zhang, J.; Chen, G. B.; Müllen, K.; Feng, X. L. Carbon-rich nanomaterials: Fascinating hydrogen and oxygen electrocatalysts. Adv. Mater.2018, 30, 1800528.

    Article  Google Scholar 

  48. Fei, H. L.; Dong, J. C.; Feng, Y. X.; Allen, C. S.; Wan, C. Z.; Volosskiy, B.; Li, M. F.; Zhao, Z. P.; Wang, Y. L.; Sun, H. T. et al. General synthesis and definitive structural identification of MN4C4 single-atom catalysts with tunable electrocatalytic activities. Nat. Catal.2018, 1, 63–72.

    Article  CAS  Google Scholar 

  49. Cai, H. Z.; Chen, B. B.; Zhang, X.; Deng, Y. C.; Xiao, D. Q.; Ma, D.; Shi, C. Highly active sites of low spin FeIIN4 species: The identification and the ORR performance. Nano Res.2021, 14, 122–130.

    Article  CAS  Google Scholar 

  50. Tu, W. Z.; Luo, W. J.; Chen, C. L.; Chen, K.; Zhu, E. B.; Zhao, Z. P.; Wang, Z. L.; Hu, T.; Zai, H. C.; Ke, X. X. et al. Tungsten as “adhesive” in Pt2CuW0.25 ternary alloy for highly durable oxygen reduction electrocatalysis. Adv. Funct. Mater.2020, 30, 1908230.

    Article  CAS  Google Scholar 

  51. Chen, C. L.; Dong, Y. Y.; Ma, J.; Zheng, L.; Zhao, Y. Z.; Chen, W. X.; Li, Y. J. Bottom-up pore-generation strategy modulated active nitrogen species for oxygen reduction reaction. Mater. Chem. Front.2021, 5, 2684–2693.

    Article  CAS  Google Scholar 

  52. Xia, B. Y.; Yan, Y.; Li, N.; Wu, H. B.; Lou, X. W.; Wang, X. A metal-organic framework-derived bifunctional oxygen electrocatalyst. Nat. Energy2016, 1, 15006.

    Article  CAS  Google Scholar 

  53. Sa, Y. J.; Seo, D. J.; Woo, J.; Lim, J. T.; Cheon, J. Y.; Yang, S. Y.; Lee, J. M.; Kang, D.; Shin, T. J.; Shin, H. S. et al. A general approach to preferential formation of active Fe-Nx sites in Fe-N/C electrocatalysts for efficient oxygen reduction reaction. J. Am. Chem. Soc.2016, 138, 15046–15056.

    Article  CAS  Google Scholar 

  54. Shen, M. X.; Wei, C. T.; Ai, K. L.; Lu, L. H. Transition metal-nitrogen-carbon nanostructured catalysts for the oxygen reduction reaction: From mechanistic insights to structural optimization. Nano Res.2017, 10, 1449–1470.

    Article  CAS  Google Scholar 

  55. Kuang, M.; Wang, Q. H.; Han, P.; Zheng, G. F. Cu, Co-Embedded N-Enriched mesoporous carbon for efficient oxygen reduction and hydrogen evolution reactions. Adv. Energy Mater.2017, 7, 1700193.

    Article  Google Scholar 

  56. Pegis, M. L.; Martin, D. J.; Wise, C. F.; Brezny, A. C.; Johnson, S. I.; Johnson, L. E.; Kumar, N.; Raugei, S.; Mayer, J. M. Mechanism of catalytic O2 reduction by iron tetraphenylporphyrin. J. Am. Chem. Soc.2019, 141, 8315–8326.

    Article  CAS  Google Scholar 

  57. Li, J. K.; Jiao, L.; Wegener, E.; Richard, L. L.; Liu, E. S.; Zitolo, A.; Sougrati, M. T.; Mukerjee, S.; Zhao, Z. P.; Huang, Y. et al. Evolution pathway from iron compounds to Fe1(II)-N4 sites through gas-phase iron during pyrolysis. J. Am. Chem. Soc.2020, 142, 1417–1423.

    Article  CAS  Google Scholar 

  58. Lin, Q. P.; Bu, X. H.; Kong, A. G.; Mao, C. Y.; Zhao, X.; Bu, F.; Feng, P. Y. New heterometallic zirconium metalloporphyrin frameworks and their heteroatom-activated high-surface-area carbon derivatives. J. Am. Chem. Soc.2015, 137, 2235–2238.

    Article  CAS  Google Scholar 

  59. Zhang, H. G.; Chung, H. T.; Cullen, D. A.; Wagner, S.; Kramm, U. I.; More, K. L.; Zelenay, P.; Wu, G. High-performance fuel cell cathodes exclusively containing atomically dispersed iron active sites. Energy Environ. Sci.2019, 12, 2548–2558.

    Article  CAS  Google Scholar 

  60. Ye, W.; Chen, S. M.; Lin, Y.; Yang, L.; Chen, S. J.; Zheng, X. S.; Qi, Z. M.; Wang, C. M.; Long, R.; Chen, M. et al. Precisely tuning the number of fe atoms in clusters on n-doped carbon toward acidic oxygen reduction reaction. Chem2019, 5, 2865–2878.

    Article  CAS  Google Scholar 

  61. Zheng, L.; Dong, Y. Y.; Chi, B.; Cui, Z. M.; Deng, Y. J.; Shi, X. D.; Du, L.; Liao, S. J. UIO-66-NH2-derived mesoporous carbon catalyst co-doped with Fe/N/S as highly efficient cathode catalyst for PEMFCs. Small2019, 15, 1803520.

    Article  Google Scholar 

  62. Chen, Z. R.; Liu, R. L.; Liu, S. H.; Huang, J. L.; Chen, L. Y.; Nadimicherla, R.; Wu, D. C.; Fu, R. W. FeS/FeNC decorated N, S-codoped porous carbon for enhanced ORR activity in alkaline media. Chem. Commun.2020, 56, 12921–12924.

    Article  CAS  Google Scholar 

  63. Sun, T. T.; Xu, L. B.; Wang, D. S.; Li, Y. D. Metal organic frameworks derived single atom catalysts for electrocatalytic energy conversion. Nano Res.2019, 12, 2067–2080.

    Article  CAS  Google Scholar 

  64. Jasinski, R. A new fuel cell cathode catalyst. Nature1964, 201, 1212–1213.

    Article  CAS  Google Scholar 

  65. Savy, M.; Andro, P.; Bernard, C.; Magner, G. Etude de la reduction de l’oxygene sur les phtalocyanines monomeres et polymeres—I. Principes fondamentaux, choix de l’ion central. Electrochim. Acta1973, 18, 191–197.

    Article  CAS  Google Scholar 

  66. Gupta, S.; Tryk, D.; Bae, I.; Aldred, W.; Yeager, E. Heat-treated polyacrylonitrile-based catalysts for oxygen electroreduction. J. Appl. Electrochem.1989, 19, 19–27.

    Article  CAS  Google Scholar 

  67. Proietti, E.; Jaouen, F.; Lefèvre, M.; Larouche, N.; Tian, J.; Herranz, J.; Dodelet, J. P. Iron-based cathode catalyst with enhanced power density in polymer electrolyte membrane fuel cells. Nat. Commun.2011, 2, 416.

    Article  Google Scholar 

  68. Varnell, J. A.; Tse, E. C. M.; Schulz, C. E.; Fister, T. T.; Haasch, R. T.; Timoshenko, J.; Frenkel, A. I.; Gewirth, A. A. Identification of carbon-encapsulated iron nanoparticles as active species in non-precious metal oxygen reduction catalysts. Nat. Commun.2016, 7, 12582.

    Article  CAS  Google Scholar 

  69. Lin, Q. P.; Bu, X. H.; Kong, A. G.; Mao, C. Y.; Bu, F.; Feng, P. Y. Heterometal-embedded organic conjugate frameworks from alternating monomeric iron and cobalt metalloporphyrins and their application in design of porous carbon catalysts. Adv. Mater.2015, 27, 3431–3436.

    Article  CAS  Google Scholar 

  70. Wang, H.; Yin, F. X.; Liu, N.; Kou, R. H.; He, X. B.; Sun, C. J.; Chen, B. H.; Liu, D. J.; Yin, H. Q. Engineering Fe-Fe3C@Fe-N-C active sites and hybrid structures from dual metal-organic frameworks for oxygen reduction reaction in H2-O2 fuel cell and Li-O2 battery. Adv. Funct. Mater.2019, 29, 1901531.

    Article  Google Scholar 

  71. Wu, G.; More, K. L.; Johnston, C. M.; Zelenay, P. Highperformance electrocatalysts for oxygen reduction derived from polyaniline, iron, and cobalt. Science2011, 332, 443–447.

    Article  CAS  Google Scholar 

  72. Kramm, U. I.; Herranz, J.; Larouche, N.; Arruda, T. M.; Lefèvre, M.; Jaouen, F.; Bogdanoff, P.; Fiechter, S.; Abs-Wurmbach, I.; Mukerjee, S. et al. Structure of the catalytic sites in Fe/N/C-catalysts for O2-reduction in PEMfuel cells. Phys. Chem. Chem. Phys.2012, 14, 11673–11688.

    Article  CAS  Google Scholar 

  73. von Deak, D.; Singh, D.; Biddinger, E. J.; King, J. C.; Bayram, B.; Miller, J. T.; Ozkan, U. S. Investigation of sulfur poisoning of CNx oxygen reduction catalysts for PEM fuel cells. J. Catal.2012, 285, 145–151.

    Article  CAS  Google Scholar 

  74. Birry, L.; Zagal, J. H.; Dodelet, J. P. Does CO poison Fe-based catalysts for ORR? Electrochem. Commun.2010, 12, 628–631.

    Article  CAS  Google Scholar 

  75. Collman, J. P.; Brauman, J. I.; Halbert, T. R.; Suslick, K. S. Nature of O2 and CO binding to metalloporphyrins and heme proteins. Proc. Natl. Acad. Sci. USA1976, 73, 3333–3337.

    Article  CAS  Google Scholar 

  76. Choi, C. H.; Choi, W. S.; Kasian, O.; Mechler, A. K.; Sougrati, M. T.; Brüller, S.; Strickland, K.; Jia, Q. Y.; Mukerjee, S.; Mayrhofer, K. J. J. et al. Unraveling the nature of sites active toward hydrogen peroxide reduction in Fe-N-C catalysts. Angew. Chem., Int. Ed.2017, 56, 8809–8812.

    Article  CAS  Google Scholar 

  77. Zang, Y. P.; Zhang, H. M.; Zhang, X.; Liu, R. R.; Liu, S. W.; Wang, G. Z.; Zhang, Y. X.; Zhao, H. J. Fe/Fe2O3 nanoparticles anchored on Fe-N-doped carbon nanosheets as bifunctional oxygen electrocatalysts for rechargeable zinc-air batteries. Nano Res.2016, 9, 2123–2137.

    Article  CAS  Google Scholar 

  78. Jin, H. H.; Zhou, H.; Ji, P. X.; Zhang, C. T.; Luo, J. H.; Zeng, W. H.; Hu, C. X.; He, D. P.; Mu, S. C. ZIF-8/LiFePO4 derived Fe-N-P Co-doped carbon nanotube encapsulated Fe2P nanoparticles for efficient oxygen reduction and Zn-air batteries. Nano Res.2020, 13, 818–823.

    Article  CAS  Google Scholar 

  79. Yang, Z. K.; Zhao, Z. W.; Liang, K.; Zhou, X.; Shen, C. C.; Liu, Y. N.; Wang, X.; Xu, A. W. Synthesis of nanoporous structured iron carbide/Fe-N-carbon composites for efficient oxygen reduction reaction in Zn-air batteries. J. Mater. Chem. A2016, 4, 19037–19044.

    Article  CAS  Google Scholar 

  80. Liu, Q. T.; Liu, X. F.; Zheng, L. R.; Shui, J. L. The solid-phase synthesis of an Fe-N-C electrocatalyst for high-power protonexchange membrane fuel cells. Angew. Chem., Int. Ed.2018, 57, 1204–1208.

    Article  CAS  Google Scholar 

  81. She, Y. Y.; Liu, J.; Wang, H. K.; Li, L.; Zhou, J. S.; Leung, M. K. H. Bubble-like Fe-encapsulated N, S-codoped carbon nanofibers as efficient bifunctional oxygen electrocatalysts for robust Zn-air batteries. Nano Res.2020, 13, 2175–2182.

    Article  Google Scholar 

  82. Liu, H. S.; Shi, Z.; Zhang, J. L.; Zhang, L.; Zhang, J. J. Ultrasonic spray pyrolyzed iron-polypyrrole mesoporous spheres for fuel celloxygen reduction electrocatalysts. J. Mater. Chem.2009, 19, 468–470.

    Article  CAS  Google Scholar 

  83. Qin, Q.; Jang, H.; Li, P.; Yuan, B.; Liu, X. E.; Cho, J. A tannic acid-derived N-, P-codoped carbon-supported iron-based nanocomposite as an advanced trifunctional electrocatalyst for the overall water splitting cells and zinc-air batteries. Adv. Energy Mater.2019, 9, 1803312.

    Article  Google Scholar 

  84. Liu, X.; Liu, H.; Chen, C.; Zou, L. L.; Li, Y.; Zhang, Q.; Yang, B.; Zou, Z. Q.; Yang, H. Fe2N nanoparticles boosting FeNx moieties for highly efficient oxygen reduction reaction in Fe-N-C porous catalyst. Nano Res.2019, 12, 1651–1657.

    Article  CAS  Google Scholar 

  85. Ao, X.; Zhang, W.; Li, Z. S.; Lv, L.; Ruan, Y. J.; Wu, H. H.; Chiang, W. H.; Wang, C. D. et al. Unraveling the high-activity nature of Fe-N-C electrocatalysts for the oxygen reduction reaction: The extraordinary synergy between Fe-N4 and Fe4N. J. Mater. Chem. A2019, 7, 11792–11801.

    Article  CAS  Google Scholar 

  86. Wang, B.; Ye, Y. Z.; Xu, L.; Quan, Y.; Wei, W. X.; Zhu, W. S.; Li, H. M.; Xia, J. X. Space-confined yolk-shell construction of Fe3O4 nanoparticles inside N-doped hollow mesoporous carbon spheres as bifunctional electrocatalysts for long-term rechargeable zinc-air batteries. Adv. Funct. Mater.2020, 30, 2005834.

    Article  CAS  Google Scholar 

  87. Li, Y. Q.; Huang, H. Y.; Chen, S. R.; Yu, X.; Wang, C.; Ma, T. L. 2D nanoplate assembled nitrogen doped hollow carbon sphere decorated with Fe3O4 as an efficient electrocatalyst for oxygen reduction reaction and Zn-air batteries. Nano Res.2019, 12, 2774–2780.

    Article  CAS  Google Scholar 

  88. Cui, X.; Gao, L. K.; Lei, S.; Liang, S.; Zhang, J. W.; Sewell, C. D.; Xue, W. D.; Liu, Q.; Lin, Z. Q.; Yang, Y. K. Simultaneously crafting single-atomic Fe sites and graphitic layer-wrapped Fe3C nanoparticles encapsulated within mesoporous carbon tubes for oxygen reduction. Adv. Funct. Mater.2020, 31, 2009197.

    Article  Google Scholar 

  89. Dai, L. M.; Xue, Y. H.; Qu, L. T.; Choi, H. J.; Baek, J. B. Metalfree catalysts for oxygen reduction reaction. Chem. Rev.2015, 115, 4823–4892.

    Article  CAS  Google Scholar 

  90. Qu, K. G.; Zheng, Y.; Dai, S.; Qiao, S. Z. Graphene oxide-polydopamine derived N, S-codoped carbon nanosheets as superior bifunctional electrocatalysts for oxygen reduction and evolution. Nano Energy2016, 19, 373–381.

    Article  CAS  Google Scholar 

  91. Ye, T. N.; Lv, L. B.; Li, X. H.; Xu, M.; Chen, J. S. Strongly veined carbon nanoleaves as a highly efficient metal-free electrocatalyst. Angew. Chem., Int. Ed.2014, 53, 6905–6909.

    Article  CAS  Google Scholar 

  92. Lv, L. B.; Ye, T. N.; Gong, L. H.; Wang, K. X.; Su, J.; Li, X. H.; Chen, J. S. Anchoring cobalt nanocrystals through the plane of graphene: Highly integrated electrocatalyst for oxygen reduction reaction. Chem. Mater.2015, 27, 544–549.

    Article  CAS  Google Scholar 

  93. Wu, Z. Y.; Xu, X. X.; Hu, B. C.; Liang, H. W.; Lin, Y.; Chen, L. F.; Yu, S. H. Iron carbide nanoparticles encapsulated in mesoporous Fe-N-doped carbon nanofibers for efficient electrocatalysis. Angew. Chem.2015, 127, 8297–8301.

    Article  Google Scholar 

  94. Wang, H. B.; Maiyalagan, T.; Wang, X. Review on recent progress in nitrogen-doped graphene: Synthesis, characterization, and its potential applications. ACS Catal.2012, 2, 781–794.

    Article  CAS  Google Scholar 

  95. Ma, T. Y.; Dai, S.; Jaroniec, M.; Qiao, S. Z. Graphitic carbon nitride nanosheet-carbon nanotube three-dimensional porous composites as high-performance oxygen evolution electrocatalysts. Angew. Chem., Int. Ed.2014, 53, 7281–7285.

    Article  CAS  Google Scholar 

  96. El-Sawy, A. M.; Mosa, I. M.; Su, D.; Guild, C. J.; Khalid, S.; Joesten, R.; Rusling, J. F.; Suib, S. L. Controlling the active sites of sulfur-doped carbon nanotube-graphene nanolobes for highly efficient oxygen evolution and reduction catalysis. Adv. Energy Mater.2016, 6, 1501966.

    Article  Google Scholar 

  97. Han, Q.; Wang, B.; Gao, J.; Cheng, Z. H.; Zhao, Y.; Zhang, Z. P.; Qu, L. T. Atomically thin mesoporous nanomesh of graphitic C3N4 for high-efficiency photocatalytic hydrogen evolution. ACS Nano2016, 10, 2745–2751.

    Article  CAS  Google Scholar 

  98. Niu, P.; Zhang, L. L.; Liu, G.; Cheng, H. M. Graphene-like carbon nitride nanosheets for improved photocatalytic activities. Adv. Funct. Mater.2012, 22, 4763–4770.

    Article  CAS  Google Scholar 

  99. Liang, J.; Zheng, Y.; Chen, J.; Liu, J.; Hulicova-Jurcakova, D.; Jaroniec, M.; Qiao, S. Z. Facile oxygen reduction on a three-dimensionally ordered macroporous graphitic C3N4/Carbon composite electrocatalyst. Angew. Chem., Int. Ed.2012, 51, 3892–3896.

    Article  CAS  Google Scholar 

  100. Hu, E. L.; Yu, X. Y.; Chen, F.; Wu, Y. D.; Hu, Y.; Lou, X. W. Graphene layers-wrapped Fe/Fe5C2 nanoparticles supported on N-doped graphene nanosheets for highly efficient oxygen reduction. Adv. Energy Mater.2018, 8, 1702476.

    Article  Google Scholar 

  101. Liu, Y. Y.; Wang, H. T.; Lin, D. C.; Zhao, J.; Liu, C.; Xie, J.; Cui, Y. A Prussian blue route to nitrogen-doped graphene aerogels as efficient electrocatalysts for oxygen reduction with enhanced active site accessibility. Nano Res.2017, 10, 1213–1222.

    Article  CAS  Google Scholar 

  102. Wu, Z. S.; Yang, S. B.; Sun, Y.; Parvez, K.; Feng, X. L.; Müllen, K. 3D nitrogen-doped graphene aerogel-supported Fe3O4 nanoparticles as efficient electrocatalysts for the oxygen reduction reaction. J. Am. Chem. Soc.2012, 134, 9082–9085.

    Article  CAS  Google Scholar 

  103. Vij, V.; Tiwari, J. N.; Lee, W. G.; Yoon, T.; Kim, K. S. Hemoglobin-carbon nanotube derived noble-metal-free Fe5C2-based catalyst for highly efficient oxygen reduction reaction. Sci. Rep.2016, 6, 20132.

    Article  CAS  Google Scholar 

  104. Bao, X. B.; Gong, Y. T.; Deng, J.; Wang, S. P.; Wang, Y. Organic-acid-assisted synthesis of a 3D lasagna-like Fe-N-doped CNTs-G framework: An efficient and stable electrocatalyst for oxygen reduction reactions. Nano Res.2017, 10, 1258–1267.

    Article  CAS  Google Scholar 

  105. Fan, X. J.; Peng, Z. W.; Ye, R. Q.; Zhou, H. Q.; Guo, X. M3C (M: Fe, Co, Ni) nanocrystals encased in graphene nanoribbons: An active and stable bifunctional electrocatalyst for oxygen reduction and hydrogen evolution reactions. ACS Nano2015, 9, 7407–7418.

    Article  CAS  Google Scholar 

  106. Hou, Y.; Huang, T. Z.; Wen, Z. H.; Mao, S.; Cui, S. M.; Chen, J. H. Metal-organic framework-derived nitrogen-doped core-shell-structured porous Fe/Fe3C@C nanoboxes supported on graphene sheets for efficient oxygen reduction reactions. Adv. Energy Mater.2014, 4, 1400337.

    Article  Google Scholar 

  107. Schnepp, Z. Biopolymers as a flexible resource for nanochemistry. Angew. Chem., Int. Ed.2013, 52, 1096–1108.

    Article  CAS  Google Scholar 

  108. Antonietti, M.; Fechler, N.; Fellinger, T. P. Carbon aerogels and monoliths: Control of porosity and nanoarchitecture via sol-gel routes. Chem. Mater.2014, 26, 196–210.

    Article  CAS  Google Scholar 

  109. Yue, H. R.; Zhao, Y. J.; Zhao, S.; Wang, B.; Ma, X. B.; Gong, J. L. A copper-phyllosilicate core-sheath nanoreactor for carbon-oxygen hydrogenolysis reactions. Nat. Commun.2013, 4, 2339.

    Article  Google Scholar 

  110. Wang, Z. L.; Xu, D.; Zhong, H. X.; Wang, J.; Meng, F. L.; Zhang, X. B. Gelatin-derived sustainable carbon-based functional materials for energy conversion and storage with controllability of structure and component. Sci. Adv.2015, 1, e1400035.

    Article  Google Scholar 

  111. Wei, J.; Liang, Y.; Hu, Y. X.; Kong, B.; Simon, G. P.; Zhang, J.; Jiang, S. P.; Wang, H. T. A versatile iron-tannin-framework ink coating strategy to fabricate biomass-derived iron carbide/Fe-N-carbon catalysts for efficient oxygen reduction. Angew. Chem., Int. Ed.2016, 55, 1355–1359.

    Article  CAS  Google Scholar 

  112. Li, Y.; Huang, J. H.; Hu, X.; Bi, L. L.; Cai, P. W.; Jia, J. C.; Chai, G. L.; Wei, S. Q.; Dai, L. M.; Wen, Z. H. Fe vacancies induced surface FeO6 in nanoarchitectures of N-doped graphene protected β-FeOOH: Effective active sites for pH-universal electrocatalytic oxygen reduction. Adv. Funct. Mater.2018, 28, 1803330.

    Article  Google Scholar 

  113. Ao, X.; Zhang, W.; Li, Z. S.; Li, J. G.; Soule, L.; Huang, X.; Chiang, W. H.; Chen, H. M.; Wang, C. D.; Liu, M. L. et al. Markedly enhanced oxygen reduction activity of single-atom Fe catalysts via integration with Fe nanoclusters. ACS Nano2019, 13, 11853–11862.

    Article  CAS  Google Scholar 

  114. Jiang, J. X.; Su, F. B.; Trewin, A.; Wood, C. D.; Niu, H. J.; Jones, J. T. A.; Khimyak, Y. Z.; Cooper, A. I. Synthetic control of the pore dimension and surface area in conjugated microporous polymer and copolymer networks. J. Am. Chem. Soc.2008, 130, 7710–7720.

    Article  CAS  Google Scholar 

  115. Xu, Y. H.; Jin, S. B.; Xu, H.; Nagai, A.; Jiang, D. L. Conjugated microporous polymers: Design, synthesis and application. Chem. Soc. Rev.2013, 42, 8012–8031.

    Article  CAS  Google Scholar 

  116. Kim, S. J.; Mahmood, J.; Kim, C.; Han, G. F.; Kim, S. W.; Jung, S. M.; Zhu, G. M.; De Yoreo, J. J.; Kim, G.; Baek, J. B. Defect-free encapsulation of Fe0 in 2D fused organic networks as a durable oxygen reduction electrocatalyst. J. Am. Chem. Soc.2018, 140, 1737–1742.

    Article  CAS  Google Scholar 

  117. Jiang, L. L.; Duan, J. J.; Zhu, J. W.; Chen, S.; Antonietti, M. Iron-cluster-directed synthesis of 2D/2D Fe-N-C/MXene superlattice-like heterostructure with enhanced oxygen reduction electrocatalysis. ACS Nano2020, 14, 2436–2444.

    Article  CAS  Google Scholar 

  118. Qiao, Y. Y.; Yuan, P. F.; Hu, Y. F.; Zhang, J. N.; Mu, S. C.; Zhou, J. H.; Li, H.; Xia, H. C.; He, J.; Xu, Q. Sulfuration of an Fe-N-C catalyst containing FexC/Fe species to enhance the catalysis of oxygen reduction in acidic media and for use in flexible Zn-air batteries. Adv. Mater.2018, 30, 1804504.

    Article  Google Scholar 

  119. Qiao, B. T.; Wang, A. Q.; Yang, X. F.; Allard, L. F.; Jiang, Z.; Cui, Y. T.; Liu, J. Y.; Li, J.; Zhang, T. Single-atom catalysis of CO oxidation using Pt1/FeOx. Nat. Chem.2011, 3, 634–641.

    Article  CAS  Google Scholar 

  120. Qu, Y. T.; Li, Z. J.; Chen, W. X.; Lin, Y.; Yuan, T. W.; Yang, Z. K.; Zhao, C. M.; Wang, J.; Zhao, C.; Wang, X. et al. Direct transformation of bulk copper into copper single sites via emitting and trapping of atoms. Nat. Catal.2018, 1, 781–786.

    Article  CAS  Google Scholar 

  121. Deng, J.; Li, H. B.; Xiao, J. P.; Tu, Y. C.; Deng, D. H.; Yang, H. X.; Tian, H. F.; Li, J. Q.; Ren, P. J.; Bao, X. H. Triggering the electrocatalytic hydrogen evolution activity of the inert two-dimensional MoS2 surface via single-atom metal doping. Energy Environ. Sci.2015, 8, 1594–1601.

    Article  CAS  Google Scholar 

  122. Lin, L. L.; Zhou, W.; Gao, R.; Yao, S. Y.; Zhang, X.; Xu, W. Q.; Zheng, S. J.; Jiang, Z.; Yu, Q. L.; Li, Y. W. et al. Low-temperature hydrogen production from water and methanol using Pt/α-MoC catalysts. Nature2017, 544, 80–83.

    Article  CAS  Google Scholar 

  123. Zhang, J. Q.; Zhao, Y. F.; Guo, X.; Chen, C.; Dong, C. L.; Liu, R. S.; Han, C. P.; Li, Y. D.; Gogotsi, Y.; Wang, G. X. Single platinum atoms immobilized on an MXene as an efficient catalyst for the hydrogen evolution reaction. Nat. Catal.2018, 1, 985–992.

    Article  CAS  Google Scholar 

  124. Zhao, L.; Zhang, Y.; Huang, L. B.; Liu, X. Z.; Zhang, Q. H.; He, C.; Wu, Z. Y.; Zhang, L. J.; Wu, J. P.; Yang, W. L. et al. Cascade anchoring strategy for general mass production of high-loading single-atomic metal-nitrogen catalysts. Nat. Commun.2019, 10, 1278.

    Article  Google Scholar 

  125. Yang, X. F.; Wang, A. Q.; Qiao, B. T.; Li, J.; Liu, J. Y.; Zhang, T. Single-atom catalysts: A new frontier in heterogeneous catalysis. Acc. Chem. Res.2013, 46, 1740–1748.

    Article  CAS  Google Scholar 

  126. Asakura, K.; Nagahiro, H.; Ichikuni, N.; Iwasawa, Y. Structure and catalytic combustion activity of atomically dispersed Pt species at MgO surface. Appl. Catal. A:Gen.1999, 188, 313–324.

    Article  CAS  Google Scholar 

  127. Zitolo, A.; Ranjbar-Sahraie, N.; Mineva, T.; Li, J. K.; Jia, Q. Y.; Stamatin, S.; Harrington, G. F.; Lyth, S. M.; Krtil, P.; Mukerjee, S. et al. Identification of catalytic sites in cobalt-nitrogen-carbon materials for the oxygen reduction reaction. Nat. Commun.2017, 8, 957.

    Article  Google Scholar 

  128. Fei, H. L.; Dong, J. C.; Arellano-Jiménez, M. J.; Ye, G. L.; Kim, N. D.; Samuel, E. L. G.; Peng, Z. W.; Zhu, Z.; Qin, F.; Bao, J. M. et al. Atomic cobalt on nitrogen-doped graphene for hydrogen generation. Nat. Commun.2015, 6, 8668.

    Article  CAS  Google Scholar 

  129. Han, Y. H.; Wang, Y. G.; Chen, W. X.; Xu, R. R.; Zheng, L. R.; Zhang, J.; Luo, J.; Shen, R. A.; Zhu, Y. Q.; Cheong, W. C. et al. Hollow N-doped carbon spheres with isolated cobalt single atomic sites: Superior electrocatalysts for oxygen reduction. J. Am. Chem. Soc.2017, 139, 17269–17272.

    Article  CAS  Google Scholar 

  130. Deng, D. H.; Chen, X. Q.; Yu, L.; Wu, X.; Liu, Q. F.; Liu, Y.; Yang, H. X.; Tian, H. F.; Hu, Y. F.; Du, P. P. et al. A single iron site confined in a graphene matrix for the catalytic oxidation of benzene at room temperature. Sci. Adv.2015, 1, e1500462.

    Article  Google Scholar 

  131. Deng, Y. J.; Chi, B.; Li, J.; Wang, G. H.; Zheng, L.; Shi, X. D.; Cui, Z. M.; Du, L.; Liao, S. J.; Zang, K. et al. Atomic Fe-doped MOF-derived carbon polyhedrons with high active-center density and ultra-high performance toward PEM fuel cells. Adv. Energy Mater.2019, 9, 1802856.

    Article  Google Scholar 

  132. Ahn, S. H.; Yu, X. W.; Manthiram, A. “Wiring” Fe-Nx-embedded porous carbon framework onto 1D nanotubes for efficient oxygen reduction reaction in alkaline and acidic media. Adv. Mater.2017, 29, 1606534.

    Article  Google Scholar 

  133. Lin, X.; Peng, P.; Guo, J. N.; Xie, L. H.; Liu, Y. J.; Xiang, Z. H. A new steric tetra-imidazole for facile synthesis of high loading atomically dispersed FeN4 electrocatalysts. Nano Energy2021, 80, 105533.

    Article  CAS  Google Scholar 

  134. Jiao, L.; Wan, G.; Zhang, R.; Zhou, H.; Yu, S. H.; Jiang, H. L. From metal-organic frameworks to single-atom Fe implanted N-doped porous carbons: Efficient oxygen reduction in both alkaline and acidic media. Angew. Chem., Int. Ed.2018, 130, 8661–8665.

    Article  Google Scholar 

  135. Zhou, H. C. J.; Kitagawa, S. Metal-organic frameworks (MOFs). Chem. Soc. Rev.2014, 43, 5415–5418.

    Article  CAS  Google Scholar 

  136. Wang, Y. R.; Huang, Q.; He, C. T.; Chen, Y. F.; Liu, J.; Shen, F. C.; Lan, Y. Q. Oriented electron transmission in polyoxometalate-metalloporphyrin organic framework for highly selective electroreduction of CO2. Nat. Commun.2018, 9, 4466.

    Article  Google Scholar 

  137. Qiao, M. F.; Wang, Y.; Wang, Q.; Hu, G. Z.; Mamat, X.; Zhang, S. S.; Wang, S. Y. Hierarchically ordered porous carbon with atomically dispersed FeN4 for ultraefficient oxygen reduction reaction in proton-exchange membrane fuel cells. Angew. Chem., Int. Ed.2020, 59, 2688–2694.

    Article  CAS  Google Scholar 

  138. Al-Zoubi, T.; Zhou, Y.; Yin, X.; Janicek, B.; Sun, C. J.; Schulz, C. E.; Zhang, X. H.; Gewirth, A. A.; Huang, P.; Zelenay, P. et al. Preparation of nonprecious metal electrocatalysts for the reduction of oxygen using a low-temperature sacrificial metal. J. Am. Chem. Soc.2020, 142, 5477–5481.

    Article  CAS  Google Scholar 

  139. Wang, J. P.; Han, G. K.; Wang, L. G.; Du, L.; Chen, G. Y.; Gao, Y. Z.; Ma, Y. L.; Du, C. Y.; Cheng, X. Q.; Zuo, P. J. et al. ZIF-8 with ferrocene encapsulated: A promising precursor to single-atom fe embedded nitrogen-doped carbon as highly efficient catalyst for oxygen electroreduction. Small2018, 14, 1704282.

    Article  Google Scholar 

  140. Zhang, H. G.; Hwang, S.; Wang, M. Y.; Feng, Z. X.; Karakalos, S.; Luo, L. L.; Qiao, Z.; Xie, X. H.; Wang, C. M.; Su, D. et al. Single atomic iron catalysts for oxygen reduction in acidic media: Particle size control and thermal activation. J. Am. Chem. Soc.2017, 139, 14143–14149.

    Article  CAS  Google Scholar 

  141. Luo, E. G.; Wang, C.; Li, Y.; Wang, X.; Gong, L. Y.; Zhao, T.; Jin, Z.; Ge, J. J.; Liu, C. P.; Xing, W. Accelerated oxygen reduction on Fe/N/C catalysts derived from precisely-designed ZIF precursors. Nano Res.2020, 13, 2420–2426.

    Article  CAS  Google Scholar 

  142. Li, J. Z.; Zhang, H. G.; Samarakoon, W.; Shan, W. T.; Cullen, D. A.; Karakalos, S.; Chen, M. J.; Gu, D. M.; More, K. L.; Wang, G. F. et al. Thermally driven structure and performance evolution of atomically dispersed FeN4 Sites for oxygen reduction. Angew. Chem., Int. Ed.2019, 131, 19147–19156.

    Article  Google Scholar 

  143. Wan, X.; Liu, X. F.; Li, Y. C.; Yu, R. H.; Zheng, L. R.; Yan, W. S.; Wang, H.; Xu, M.; Shui, J. L. Fe-N-C electrocatalyst with dense active sites and efficient mass transport for high-performance proton exchange membrane fuel cells. Nat. Catal.2019, 2, 259–268.

    Article  CAS  Google Scholar 

  144. Han, J. X.; Meng, X. Y.; Lu, L.; Bian, J. J.; Li, Z. P.; Sun, C. W. Single-atom Fe-Nx-C as an efficient electrocatalyst for zinc-air batteries. Adv. Funct. Mater.2019, 29, 1808872.

    Article  CAS  Google Scholar 

  145. Hou, C. C.; Zou, L. L.; Sun, L. M.; Zhang, K. X.; Liu, Z.; Li, Y. W.; Li, C. X.; Zou, R. Q.; Yu, J. H.; Xu, Q. Single-atom iron catalysts on overhang-eave carbon cages for high-performance oxygen reduction reaction. Angew. Chem., Int. Ed.2020, 132, 7454–7459.

    Article  Google Scholar 

  146. Chen, Y. J.; Ji, S. F.; Wang, Y. G.; Dong, J. C.; Chen, W. X.; Li, Z.; Shen, R. G.; Zheng, L. R.; Zhuang, Z. B.; Wang, D. S. et al. Isolated single iron atoms anchored on N-doped porous carbon as an efficient electrocatalyst for the oxygen reduction reaction. Angew. Chem., Int. Ed.2017, 129, 7041–7045.

    Article  Google Scholar 

  147. Ferrero, G. A.; Preuss, K.; Marinovic, A.; Jorge, A. B.; Mansor, N.; Brett, D. J. L.; Fuertes, A. B.; Sevilla, M.; Titirici, M. M. Fe-N-doped carbon capsules with outstanding electrochemical performance and stability for the oxygen reduction reaction in both acid and alkaline conditions. ACS Nano2016, 10, 5922–5932.

    Article  CAS  Google Scholar 

  148. Chen, Y. F.; Li, Z. J.; Zhu, Y. B.; Sun, D. M.; Liu, X. E.; Xu, L.; Tang, Y. W. Atomic Fe dispersed on N-doped carbon hollow nanospheres for high-efficiency electrocatalytic oxygen reduction. Adv. Mater.2019, 31, 1806312.

    Article  Google Scholar 

  149. Chen, G. B.; Liu, P.; Liao, Z. Q.; Sun, F. F.; He, Y. H.; Zhong, H. X.; Zhang, T.; Zschech, E.; Chen, M. W.; Wu, G. et al. Zinc-mediated template synthesis of Fe-N-C electrocatalysts with densely accessible Fe-Nx active sites for efficient oxygen reduction. Adv. Mater.2020, 32, 1907399.

    Article  CAS  Google Scholar 

  150. Meng, F. L.; Wang, Z. L.; Zhong, H. X.; Wang, J.; Yan, J. M.; Zhang, X. B. Reactive multifunctional template-induced preparation of Fe-N-doped mesoporous carbon microspheres towards highly efficient electrocatalysts for oxygen reduction. Adv. Mater.2016, 28, 7948–7955.

    Article  CAS  Google Scholar 

  151. Huang, Z.; Pan, H. Y.; Yang, W. J.; Zhou, H. H.; Gao, N.; Fu, C. P.; Li, S. C.; Li, H. X.; Kuang, Y. F. In situ self-template synthesis of Fe-N-doped double-shelled hollow carbon microspheres for oxygen reduction reaction. ACS Nano2018, 12, 208–216.

    Article  CAS  Google Scholar 

  152. Zhang, X. Y.; Zhang, S.; Yang, Y.; Wang, L. G.; Mu, Z. J.; Zhu, H. S.; Zhu, X. Q.; Xing, H. H.; Xia, H. Y.; Huang, B. L. et al. A general method for transition metal single atoms anchored on honeycomb-like nitrogen-doped carbon nanosheets. Adv. Mater.2020, 32, 1906905.

    Article  CAS  Google Scholar 

  153. Chen, Z. W.; Higgins, D.; Yu, A. P.; Zhang, L.; Zhang, J. J. A review on non-precious metal electrocatalysts for PEMfuelcells. Energy Environ. Sci.2011, 4, 3167–3192.

    Article  CAS  Google Scholar 

  154. Qu, Y. T.; Wang, L. G.; Li, Z. J.; Li, P.; Zhang, Q. H.; Lin, Y.; Zhou, F. Y.; Wang, H. J.; Yang, Z. K.; Hu, Y. D. et al. Ambient synthesis of single-atom catalysts from bulk metal via trapping of atoms by surface dangling bonds. Adv. Mater.2019, 31, 1904496.

    Article  CAS  Google Scholar 

  155. Ding, R.; Liu, Y. D.; Rui, Z. Y.; Li, J.; Liu, J. G.; Zou, Z. G. Facile grafting strategy synthesis of single-atom electrocatalyst with enhanced ORR performance. Nano Res.2020, 13, 1519–1526.

    Article  CAS  Google Scholar 

  156. Peng, P.; Shi, L.; Huo, F.; Mi, C. X.; Wu, X. H.; Zhang, S. J.; Xiang, Z. H. A pyrolysis-free path toward superiorly catalytic nitrogen-coordinated single atom. Sci. Adv.2019, 5, eaaw2322.

    Article  CAS  Google Scholar 

  157. Li, W. M.; Yu, A. P.; Higgins, D. C.; Llanos, B. G.; Chen, Z. W. Biologically inspired highly durable iron phthalocyanine catalysts for oxygen reduction reaction in polymer electrolyte membrane fuel cells. J. Am. Chem. Soc.2010, 132, 17056–17058.

    Article  CAS  Google Scholar 

  158. Cao, R. G.; Thapa, R.; Kim, H.; Xu, X. D.; Kim, M. G.; Li, Q.; Park, N.; Liu, M. L.; Cho, J. Promotion of oxygen reduction by a bio-inspired tethered iron phthalocyanine carbon nanotube-based catalyst. Nat. Commun.2013, 4, 2076.

    Article  Google Scholar 

  159. Wang, X. X.; Wang, B.; Zhong, J.; Zhao, F. P.; Han, N.; Huang, W. J.; Zeng, M.; Fan, J.; Li, Y. G. Iron polyphthalocyanine sheathed multiwalled carbon nanotubes: A high-performance electrocatalyst for oxygen reduction reaction. Nano Res.2016, 9, 1497–1506.

    Article  CAS  Google Scholar 

  160. Wan, W. C.; Triana, C. A.; Lan, J. G.; Li, J. G.; Allen, C. S.; Zhao, Y. G.; Iannuzzi, M.; Patzke, G. R. Bifunctional single atom electrocatalysts: Coordination-performance correlations and reaction pathways. ACS Nano2020, 14, 13279–13293.

    Article  CAS  Google Scholar 

  161. Pan, Y.; Lin, R.; Chen, Y. J.; Liu, S. J.; Zhu, W.; Cao, X.; Chen, W. X.; Wu, K. L.; Cheong, W. C.; Wang, Y. et al. Design of singleatom Co-N5 catalytic site: A robust electrocatalyst for CO2 reduction with nearly 100% CO selectivity and remarkable stability. J. Am. Chem. Soc.2018, 140, 4218–4221.

    Article  CAS  Google Scholar 

  162. Jiang, K.; Siahrostami, S.; Zheng, T. T.; Hu, Y. F.; Hwang, S.; Stavitski, E.; Peng, Y. D.; Dynes, J.; Gangisetty, M.; Su, D. et al. Isolated Ni single atoms in graphene nanosheets for highperformance CO2 reduction. Energy Environ. Sci.2018, 11, 893–903.

    Article  CAS  Google Scholar 

  163. Meng, F. L.; Zhong, H. X.; Yan, J. M.; Zhang, X. B. Iron-chelated hydrogel-derived bifunctional oxygen electrocatalyst for highperformance rechargeable Zn-air batteries. Nano Res.2017, 10, 4436–4447.

    Article  CAS  Google Scholar 

  164. Gong, L. Y.; Zhang, H.; Wang, Y.; Luo, E. G.; Li, K.; Gao, L. Q.; Wang, Y. M.; Wu, Z. J.; Jin, Z.; Ge, J. J. et al. Bridge bonded oxygen ligands between approximated FeN4 sites confer catalysts with high ORR performance. Angew. Chem., Int. Ed.2020, 132, 14027–14032.

    Article  Google Scholar 

  165. Miao, Z. P.; Wang, X. M.; Tsai, M. C.; Jin, Q. Q.; Liang, J. S.; Ma, F.; Wang, T. Y.; Zheng, S. J.; Hwang, B. J.; Huang, Y. H. et al. Atomically dispersed Fe-N/C electrocatalyst boosts oxygen catalysis via a new metal-organic polymer supramolecule strategy. Adv. Energy Mater.2018, 8, 1801226.

    Article  Google Scholar 

  166. Yasuda, S.; Furuya, A.; Uchibori, Y.; Kim, J.; Murakoshi, K. Iron-nitrogen-doped vertically aligned carbon nanotube electrocatalyst for the oxygen reduction reaction. Adv. Funct. Mater.2016, 26, 738–744.

    Article  CAS  Google Scholar 

  167. Jiao, L.; Zhang, R.; Wan, G.; Yang, W. J.; Wan, X.; Zhou, H.; Shui, J. L.; Yu, S. H.; Jiang, H. L. Nanocasting SiO2 into metal-organic frameworks imparts dual protection to high-loading Fe single-atom electrocatalysts. Nat. Commun.2020, 11, 2831.

    Article  CAS  Google Scholar 

  168. Zitolo, A.; Goellner, V.; Armel, V.; Sougrati, M. T.; Mineva, T.; Stievano, L.; Fonda, E.; Jaouen, F. Identification of catalytic sites for oxygen reduction in iron-and nitrogen-doped graphene materials. Nat. Mater.2015, 14, 937–942.

    Article  CAS  Google Scholar 

  169. Yang, X.; Xia, D. S.; Kang, Y. Q.; Du, H. D.; Kang, F. Y.; Gan, L.; Li, J. Unveiling the Axial hydroxyl ligand on Fe-N4-C electrocatalysts and its impact on the pH-dependent oxygen reduction activities and poisoning kinetics. Adv. Sci.2020, 7, 2000176.

    Article  CAS  Google Scholar 

  170. Wang, Y.; Tang, Y. J.; Zhou, K. Self-adjusting activity induced by intrinsic reaction intermediate in Fe-N-C single-atom catalysts. J. Am. Chem. Soc.2019, 141, 14115–14119.

    Article  CAS  Google Scholar 

  171. Holby, E. F.; Taylor, C. D. Activity of N-coordinated multi-metal-atom active site structures for Pt-free oxygen reduction reaction catalysis: Role of *OH ligands. Sci. Rep.2015, 5, 9286.

    Article  Google Scholar 

  172. Jia, Q. Y.; Ramaswamy, N.; Hafiz, H.; Tylus, U.; Strickland, K.; Wu, G.; Barbiellini, B.; Bansil, A.; Holby, E. F.; Zelenay, P. et al. Experimental observation of redox-induced Fe-N switching behavior as a determinant role for oxygen reduction activity. ACS Nano2015, 9, 12496–12505.

    Article  CAS  Google Scholar 

  173. Wang, J.; Huang, Z. Q.; Liu, W.; Chang, C. R.; Tang, H. L.; Li, Z. J.; Chen, W. X.; Jia, C. J.; Yao, T.; Wei, S. Q. et al. Design of N-coordinated dual-metal sites: A stable and active Pt-free catalyst for acidic oxygen reduction reaction. J. Am. Chem. Soc.2017, 139, 17281–17284.

    Article  CAS  Google Scholar 

  174. Holby, E. F.; Wang, G. F.; Zelenay, P. Acid stability and demetalation of PGM-free ORR electrocatalyst structures from density functional theory: A model for “single-atom catalyst” dissolution. ACS Catal.2020, 10, 14527–14539.

    Article  CAS  Google Scholar 

  175. Han, A. J.; Chen, W. X.; Zhang, S. L.; Zhang, M. L.; Han, Y. H.; Zhang, J.; Ji, S. F.; Zheng, L. R.; Wang, Y.; Gu, L. et al. A polymer encapsulation strategy to synthesize porous nitrogen-doped carbon-nanosphere-supported metal isolated-single-atomic-site catalysts. Adv. Mater.2018, 30, 1706508.

    Article  Google Scholar 

  176. Jiang, R.; Li, L.; Sheng, T.; Hu, G. F.; Chen, Y. G.; Wang, L. Y. Edge-site engineering of atomically dispersed Fe-N4 by selective C-N bond cleavage for enhanced oxygen reduction reaction activities. J. Am. Chem. Soc.2018, 140, 11594–11598.

    Article  CAS  Google Scholar 

  177. Wang, X.; Jia, Y.; Mao, X.; Liu, D. B.; He, W. X.; Li, J.; Liu, J. G.; Yan, X. C.; Chen, J.; Song, L. et al. Edge-rich Fe-N4 active sites in defective carbon for oxygen reduction catalysis. Adv. Mater.2020, 32, 2000966.

    Article  CAS  Google Scholar 

  178. Xiao, M. L.; Xing, Z. H.; Jin, Z.; Liu, C. P.; Ge, J. J.; Zhu, J. B.; Wang, Y.; Zhao, X.; Chen, Z. W. Preferentially engineering FeN4 edge sites onto graphitic nanosheets for highly active and durable oxygen electrocatalysis in rechargeable Zn-air batteries. Adv. Mater.2020, 32, 2004900.

    Article  CAS  Google Scholar 

  179. Jia, Y.; Zhang, L. Z.; Du, A. J.; Gao, G. P.; Chen, J.; Yan, X. C.; Brown, C. L.; Yao, X. D. Defect graphene as a trifunctional catalyst for electrochemical reactions. Adv. Mater.2016, 28, 9532–9538.

    Article  CAS  Google Scholar 

  180. Su, P. P.; Huang, W. J.; Zhang, J. W.; Guharoy, U.; Du, Q. G.; Sun, Q.; Jiang, Q. K.; Cheng, Y.; Yang, J.; Zhang, X. L. et al. Fe atoms anchored on defective nitrogen doped hollow carbon spheres as efficient electrocatalysts for oxygen reduction reaction. Nano Res.2021, 14, 1069–1077.

    Article  CAS  Google Scholar 

  181. Li, Q. H.; Chen, W. X.; Xiao, H.; Gong, Y.; Li, Z.; Zheng, L. R.; Zheng, X. S.; Yan, W. S.; Cheong, W. C.; Shen, R. G. et al. Fe isolated single atoms on S, N codoped carbon by copolymer pyrolysis strategy for highly efficient oxygen reduction reaction. Adv. Mater.2018, 30, 1800588.

    Article  Google Scholar 

  182. Chen, Y. J.; Ji, S. F.; Zhao, S.; Chen, W. X.; Dong, J. C.; Cheong, W. C.; Shen, R. G.; Wen, X. D.; Zheng, L. R.; Rykov, A. I. et al. Enhanced oxygen reduction with single-atomic-site iron catalysts for a zinc-air battery and hydrogen-air fuel cell. Nat. Commun.2018, 9, 5422.

    Article  CAS  Google Scholar 

  183. Zhang, J. Q.; Zhao, Y. F.; Chen, C.; Huang, Y. C.; Dong, C. L.; Chen, C. J.; Liu, R. S.; Wang, C. Y.; Yan, K.; Li, Y. D. et al. Tuning the coordination environment in single-atom catalysts to achieve highly efficient oxygen reduction reactions. J. Am. Chem. Soc.2019, 141, 20118–20126.

    Article  CAS  Google Scholar 

  184. Mun, Y. D.; Lee, S.; Kim, K.; Kim, S.; Lee, S.; Han, J. W.; Lee, J. 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.2019, 141, 6254–6262.

    Article  CAS  Google Scholar 

  185. Shen, H. J.; Gracia-Espino, E.; Ma, J. Y.; Zang, K. T.; Luo, J.; Wang, L.; Gao, S. S.; Mamat, X.; Hu, G. Z.; Wagberg, T. et al. Synergistic effects between atomically dispersed Fe-N-C and C-S-C for the oxygen reduction reaction in acidic media. Angew. Chem., Int. Ed.2017, 129, 13988–13992.

    Article  Google Scholar 

  186. Shen, H. J.; Gracia-Espino, E.; Ma, J. Y.; Tang, H. D.; Mamat, X.; Wagberg, T.; Hu, G. Z.; Guo, S. J. Atomically FeN2 moieties dispersed on mesoporous carbon: A new atomic catalyst for efficient oxygen reduction catalysis. Nano Energy2017, 35, 9–16.

    Article  CAS  Google Scholar 

  187. Yin, P. Q.; Yao, T.; Wu, Y.; Zheng, L. R.; Lin, Y.; Liu, W.; Ju, H. X.; Zhu, J. F.; Hong, X.; Deng, Z. X. et al. Single cobalt atoms with precise N-coordination as superior oxygen reduction reaction catalysts. Angew. Chem., Int. Ed.2016, 55, 10800–10805.

    Article  CAS  Google Scholar 

  188. Zhu, C. Z.; Shi, Q. R.; Xu, B. Z.; Fu, S. F.; Wan, G.; Yang, C.; Yao, S. Y.; Song, J. H.; Zhou, H.; Du, D. et al. Hierarchically porous M-N-C (M = Co and Fe) single-atom electrocatalysts with robust MNx. active moieties enable enhanced ORR performance. Adv. Energy Mater.2018, 8, 1801956.

    Article  Google Scholar 

  189. Li, F.; Han, G. F.; Bu, Y. F.; Noh, H. J.; Jeon, J. P.; Shin, T. J.; Kim, S. J.; Wu, Y.; Jeong, H. Y.; Fu, Z. P. et al. Revealing isolated M-N3C1 active sites for efficient collaborative oxygen reduction catalysis. Angew. Chem., Int. Ed.2020, 59, 23678–23683.

    Article  CAS  Google Scholar 

  190. Li, Y. C.; Liu, X. F.; Zheng, L. R.; Shang, J. X.; Wan, X.; Hu, R. M.; Guo, X.; Hong, S.; Shui, J. L. Preparation of Fe-N-C catalysts with FeNx (x = 1, 3, 4) active sites and comparison of their activities for the oxygen reduction reaction and performances in proton exchange membrane fuel cells. J. Mater. Chem. A2019, 7, 26147–26153.

    Article  CAS  Google Scholar 

  191. Lin, Y. C.; Liu, P. Y.; Velasco, E.; Yao, G.; Tian, Z. Q.; Zhang, L. J.; Chen, L. Fabricating single-atom catalysts from chelating metal in open frameworks. Adv. Mater.2019, 31, 1808193.

    Article  Google Scholar 

  192. Singh, K. P.; Bae, E. J.; Yu, J. S. Fe-P: A new class of electroactive catalyst for oxygen reduction reaction. J. Am. Chem. Soc.2015, 137, 3165–3168.

    Article  CAS  Google Scholar 

  193. Han, Y. H.; Wang, Y. G.; Xu, R. R.; Chen, W. X.; Zheng, L. R.; Han, A. J.; Zhu, Y. Q.; Zhang, J.; Zhang, H. B.; Luo, J. et al. Electronic structure engineering to boost oxygen reduction activity by controlling the coordination of the central metal. Energy Environ. Sci.2018, 11, 2348–2352.

    Article  CAS  Google Scholar 

  194. Li, X. C.; Yang, X. X.; Liu, L. T.; Zhao, H.; Li, Y. W.; Zhu, H.; Chen, Y. Z.; Guo, S. W.; Liu, Y. N.; Tan, Q. et al. Chemical vapor deposition for N/S-doped single fe site catalysts for the oxygen reduction in direct methanol fuel cells. ACS Catal.2021, 7450–7459.

  195. Zhu, X. F.; Tan, X.; Wu, K. H.; Chiang, C. L.; Lin, Y. C.; Lin, Y. G.; Wang, D. W.; Smith, S.; Lu, X. Y.; Amal, R. N, P co-coordinated Fe species embedded in carbon hollow spheres for oxygen electrocatalysis. J. Mater. Chem. A2019, 7, 14732–14742.

    Article  CAS  Google Scholar 

  196. Yuan, K.; Lützenkirchen-Hecht, D.; Li, L. B.; Shuai, L.; Li, Y. Z.; Cao, R.; Qiu, M.; Zhuang, X. D.; Leung, M. K. H.; Chen, Y. W. et al. Boosting oxygen reduction of single iron active sites via geometric and electronic engineering: Nitrogen and phosphorus dual coordination. J. Am. Chem. Soc.2020, 142, 2404–2412.

    Article  CAS  Google Scholar 

  197. Jin, H. H.; Kou, Z. K.; Cai, W. W.; Zhou, H.; Ji, P. X.; Liu, B. S.; Radwan, A.; He, D. P.; Mu, S. C. P-Fe bond oxygen reduction catalysts toward high-efficiency metal-air batteries and fuel cells. J. Mater. Chem. A2020, 8, 9121–9127.

    Article  CAS  Google Scholar 

  198. Fang, G. Z.; Wang, Q. C.; Zhou, J.; Lei, Y. P.; Chen, Z. X.; Wang, Z. Q.; Pan, A. Q.; Liang, S. Q. Metal organic framework-templated synthesis of bimetallic selenides with rich phase boundaries for sodium-ion storage and oxygen evolution reaction. ACS Nano2019, 13, 5635–5645.

    Article  CAS  Google Scholar 

  199. Yang, L.; Lv, Y. L.; Cao, D. P. Co, N-codoped nanotube/graphene 1D/2D heterostructure for efficient oxygen reduction and hydrogen evolution reactions. J. Mater. Chem. A2018, 6, 3926–3932.

    Article  CAS  Google Scholar 

  200. Medford, A. J.; Vojvodic, A.; Hummelshøj, J. S.; Voss, J.; Abild-Pedersen, F.; Studt, F.; Bligaard, T.; Nilsson, A.; Nørskov, J. K. From the Sabatier principle to a predictive theory of transition-metal heterogeneous catalysis. J. Catal.2015, 328, 36–42.

    Article  CAS  Google Scholar 

  201. Wang, X. X.; Cullen, D. A.; Pan, Y. T.; Hwang, S.; Wang, M. Y.; Feng, Z. X.; Wang, J. Y.; Engelhard, M. H.; Zhang, H. G.; He, Y. H. et al. Nitrogen-coordinated single cobalt atom catalysts for oxygen reduction in proton exchange membrane fuel cells. Adv. Mater.2018, 30, 1706758.

    Article  Google Scholar 

  202. Zagal, J. H.; Koper, M. T. M. Reactivity descriptors for the activity of molecular MN4 catalysts for the oxygen reduction reaction. Angew. Chem., Int. Ed.2016, 55, 14510–14521.

    Article  CAS  Google Scholar 

  203. Ma, Y.; Li, J. T.; Liao, X. B.; Luo, W.; Huang, W. Z.; Meng, J. S.; Chen, Q.; Xi, S. B.; Yu, R. H.; Zhao, Y. et al. Heterostructure design in bimetallic phthalocyanine boosts oxygen reduction reaction activity and durability. Adv. Funct. Mater.2020, 30, 2005000.

    Article  CAS  Google Scholar 

  204. Liu, W. P.; Hou, Y. X.; Pan, H. H.; Liu, W. B.; Qi, D. D.; Wang, K.; Jiang, J. Z.; Yao, X. D. An ethynyl-linked Fe/Co heterometallic phthalocyanine conjugated polymer for the oxygen reduction reaction. J. Mater. Chem. A2018, 6, 8349–8357.

    Article  CAS  Google Scholar 

  205. Wang, J.; Liu, W.; Luo, G.; Li, Z. J.; Zhao, C.; Zhang, H. R.; Zhu, M. Z.; Xu, Q.; Wang, X. Q.; Zhao, C. M. et al. Synergistic effect of well-defined dual sites boosting the oxygen reduction reaction. Energy Environ. Sci.2018, 11, 3375–3379.

    Article  CAS  Google Scholar 

  206. Yang, G. G.; Zhu, J. W.; Yuan, P. F.; Hu, Y. F.; Qu, G.; Lu, B. A.; Xue, X. Y.; Yin, H. B.; Cheng, W. Z.; Cheng, J. Q. et al. Regulating Fe-spin state by atomically dispersed Mn-N in Fe-N-C catalysts with high oxygen reduction activity. Nat. Commun.2021, 12, 1734.

    Article  CAS  Google Scholar 

  207. Sun, Y. L.; Wang, J.; Liu, Q.; Xia, M. R.; Tang, Y. F.; Gao, F. M.; Hou, Y. L.; Tse, J.; Zhao, Y. F. Itinerant ferromagnetic half metallic cobalt-iron couples: Promising bifunctional electrocatalysts for ORR and OER. J. Mater. Chem. A2019, 7, 27175–27185.

    Article  CAS  Google Scholar 

  208. Li, Z. L.; Zhuang, Z. C.; Lv, F.; Zhu, H.; Zhou, L.; Luo, M. C.; Zhu, J. X.; Lang, Z. Q.; Feng, S. H.; Chen, W. et al. The marriage of the FeN4 moiety and mxene boosts oxygen reduction catalysis: Fe 3d electron delocalization matters. Adv. Mater.2018, 30, 1803220.

    Article  Google Scholar 

  209. Zhang, J. C.; Yang, H. B.; Liu, B. Coordination engineering of single-atom catalysts for the oxygen reduction reaction: A review. Adv. Energy Mater.2021, 11, 2002473.

    Article  CAS  Google Scholar 

  210. Kramm, U. I.; Herrmann-Geppert, I.; Behrends, J.; Lips, K.; Fiechter, S.; Bogdanoff, P. 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.2016, 138, 635–640.

    Article  CAS  Google Scholar 

  211. Shi, C. W.; Liu, Y. H.; Qi, R. Y.; Li, J. T.; Zhu, J. X.; Yu, R. H.; Li, S. D.; Hong, X. F.; Wu, J. S.; Xi, S. B. et al. Hierarchical N-doped carbon spheres anchored with cobalt nanocrystals and single atoms for oxygen reduction reaction. Nano Energy2021, 87, 106153.

    Article  CAS  Google Scholar 

  212. Chong, L. N.; Wen, J. G.; Kubal, J.; Sen, F. G.; Zou, J. X.; Greeley, J.; Chan, M.; Barkholtz, H.; Ding, W. J.; Liu, D. J. Ultralow-loading platinum-cobalt fuel cell catalysts derived from imidazolate frameworks. Science2018, 362, 1276–1281.

    Article  CAS  Google Scholar 

  213. Ao, X.; Zhang, W.; Zhao, B. T.; Ding, Y.; Nam, G.; Soule, L.; Abdelhafiz, A.; Wang, C. D.; Liu, M. L. Atomically dispersed Fe-N-C decorated with Pt-alloy core-shell nanoparticles for improved activity and durability towards oxygen reduction. Energy Environ. Sci.2020, 13, 3032–3040.

    Article  CAS  Google Scholar 

  214. Wang, Z. H.; Jin, H. H.; Meng, T.; Liao, K.; Meng, W. Q.; Yang, J. L.; He, D. P.; Xiong, Y. L.; Mu, S. C. Fe, Cu-coordinated ZIF-derived carbon framework for efficient oxygen reduction reaction and zinc-air batteries. Adv. Funct. Mater.2018, 28, 1802596.

    Article  Google Scholar 

  215. Ibraheem, S.; Chen, S. G.; Li, J.; Wang, Q. M.; Wei, Z. D. In situ growth of vertically aligned FeCoOOH-nanosheets/nanoflowers on Fe, N co-doped 3D-porous carbon as efficient bifunctional electrocatalysts for rechargeable zinc-O2 batteries. J. Mater. Chem. A2019, 7, 9497–9502.

    Article  CAS  Google Scholar 

  216. Lin, G. Q.; Ding, H. M.; Yuan, D. Q.; Wang, B. S.; Wang, C. A pyrene-based, fluorescent three-dimensional covalent organic framework. J. Am. Chem. Soc.2016, 138, 3302–3305.

    Article  CAS  Google Scholar 

  217. Huang, N.; Zhai, L. P.; Coupry, D. E.; Addicoat, M. A.; Okushita, K.; Nishimura, K.; Heine, T.; Jiang, D. L. Multiple-component covalent organic frameworks. Nat. Commun.2016, 7, 12325.

    Article  Google Scholar 

  218. Li, L. Y.; Li, L.; Cui, C. Y.; Fan, H. J.; Wang, R. H. Heteroatom-doped carbon spheres from hierarchical hollow covalent organic framework precursors for metal-free catalysis. ChemSusChem2017, 10, 4921–4926.

    Article  CAS  Google Scholar 

  219. Jiang, W. J.; Gu, L.; Li, L.; Zhang, Y.; Zhang, X.; Zhang, L. J.; Wang, J. Q.; Hu, J. S.; Wei, Z. D.; Wan, L. J. Understanding the high activity of Fe-N-C electrocatalysts in oxygen reduction: Fe/Fe3C nanoparticles boost the activity of Fe-Nx. J. Am. Chem. Soc.2016, 138, 3570–3578.

    Article  CAS  Google Scholar 

  220. Wang, M.; Yang, Y. S.; Liu, X. B.; Pu, Z. H.; Kou, Z. K.; Zhu, P. P.; Mu, S. C. The role of iron nitrides in the Fe-N-C catalysis system towards the oxygen reduction reaction. Nanoscale2017, 9, 7641–7649.

    Article  CAS  Google Scholar 

  221. Xiao, J. W.; Xu, Y. Y.; Xia, Y. T.; Xi, J. B.; Wang, S. Ultra-small Fe2N nanocrystals embedded into mesoporous nitrogen-doped graphitic carbon spheres as a highly active, stable, and methanoltolerant electrocatalyst for the oxygen reduction reaction. Nano Energy2016, 24, 121–129.

    Article  CAS  Google Scholar 

  222. Guo, J. N.; Li, Y.; Cheng, Y. H.; Dai, L. M.; Xiang, Z. H. Highly efficient oxygen reduction reaction electrocatalysts synthesized under nanospace confinement of metal-organic framework. ACS Nano2017, 11, 8379–8386.

    Article  CAS  Google Scholar 

  223. Gong, X. F.; Zhu, J. B.; Li, J. Z.; Gao, R.; Zhou, Q. Y.; Zhang, Z.; Dou, H. Z.; Zhao, L.; Sui, X. L.; Cai, J. J. et al. Self-templated hierarchically porous carbon nanorods embedded with atomic Fe-N4 active sites as efficient oxygen reduction electrocatalysts in Zn-air batteries. Adv. Funct. Mater.2020, 31, 2008085.

    Article  Google Scholar 

  224. Ma, S. Q.; Goenaga, G. A.; Call, A. V.; Liu D. J. Cobalt imidazolate framework as precursor for oxygen reduction reaction electrocatalysts. Chem. Eur. J.2011, 17, 2063–2067.

    Article  CAS  Google Scholar 

  225. Shui, J. L.; Chen, C.; Grabstanowicz, L., Zhao, D.; Liu, D. J. Highly efficient nonprecious metal catalyst prepared with metal-organic framework in a continuous carbon nanofibrous network. Proc. Natl. Acad. Sci. USA2015, 112, 10629–10643.

    Article  CAS  Google Scholar 

Download references

Acknowledgements

W. X. C. acknowledges the National Natural Science Foundation of China (No. 21801015). W. X. C. acknowledges the Beijing Institute of Technology Research Fund Program for Young Scholars (No. 3090012221909).

Author information

Authors and Affiliations

  1. Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, Experimental Center of Advanced Materials, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081, China

    Mengru Sun, Changli Chen, Menghao Wu, Danni Zhou, Zhiyi Sun, Wenxing Chen & Yujing Li

  2. Department of Physics and Engineering Technology, Guilin Normal College, Guilin, 541199, China

    Jianling Fan

Authors
  1. Mengru Sun
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Changli Chen
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Menghao Wu
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Danni Zhou
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Zhiyi Sun
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Jianling Fan
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Wenxing Chen
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Yujing Li
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding authors

Correspondence to Jianling Fan, Wenxing Chen or Yujing Li.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Sun, M., Chen, C., Wu, M. et al. Rational design of Fe-N-C electrocatalysts for oxygen reduction reaction: From nanoparticles to single atoms. Nano Res. 15, 1753–1778 (2022). https://doi.org/10.1007/s12274-021-3827-8

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s12274-021-3827-8

Keywords

Search

Navigation