Corresponding Author

Xin-sheng ZHANG(xszhang@ecust.edu.cn);
Shi-gang SUN(sgsun@xmu.edu.cn)


The development of Fe/N/C electrocatalyst for oxygen reduction reaction (ORR) is vital for the large-scale applications of proton exchange membrane fuel cells. Understanding the active site structure will contribute to the rational design of highly active catalysts. In this study, the as-prepared Fe/N/C catalyst based on poly-m-phenylenediamine (PmPDA-FeNx/C) catalyst with the high ORR activity was subjected to the high-temperature heat treatment again at 1000 ~1500 oC. The degradation of in the ORR activity of PmPDA-FeNx/C by with various heat treatments was correlated to the change of elemental compositions, chemical states and textural properties. As the temperature elevated, the Fe atoms aggregated to form nanoparticles, while the gaseous N-containing species volatilized and the amount of N contents decreased, resulting in the destruction of active sites. The XPS analysis revealed that the content of N species with low binding energy show good positive correlation with the ORR kinetic current of catalyst, demonstrating that the pyridinic N and Fe-N species are probably main components of active sites and contribute to the high ORR activity. This study provides a new strategy to investigate the nature of active centre.

Graphical Abstract


Fe/N/C electrocatalyst, oxygen reduction reaction, active sites, pyridinic N, Fe-N species

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[1] Wang Y, Chen K S, Mishler J, et al. A Review of Polymer Electrolyte Membrane Fuel Cells: Technology, Applications, and Needs on Fundamental Research[J]. Applied Energy, 2011, 88(4): 981-1007.

[2] Stephens I E L, Bondarenko A S, Grønbjerg U, et al. Understanding the Electrocatalysis of Oxygen Reduction on Platinum and Its Alloys[J]. Energy & Environmental Science, 2012, 5(5): 6744-6762.

[3] Wu G, Santandreu A, Kellogg W, et al. Carbon Nanocomposite Catalysts for Oxygen Reduction and Evolution Reactions: From Nitrogen Doping to Transition-Metal Addition[J]. Nano Energy, 2016, 29: 83-110.

[4] Shao M H, Chang Q W, Dodelet J P, et al. Recent Advances in Electrocatalysts for Oxygen Reduction Reaction[J]. Chemical Reviews, 2016, 116(6): 3594-3657.

[5] Thorum M S, Hankett J M, Gewirth A A. Poisoning the Oxygen Reduction Reaction on Carbon-Supported Fe and Cu Electrocatalysts: Evidence for Metal-Centered Activity[J]. Journal of Physical Chemistry Letters, 2011, 2(4): 295-298.

[6] Li W M, Wu J, Higgins D C, et al. Determination of Iron Active Sites in Pyrolyzed Iron-Based Catalysts for the Oxygen Reduction Reaction[J]. ACS Catalysis, 2012, 2(12): 2761-2768.

[7] Duan J J, Chen S, Jaroniec M, et al. Heteroatom-Doped Graphene-Based Materials for Energy-Relevant Electrocatalytic Processes[J]. ACS Catalysis, 2015, 5(9): 5207-5234.

[8] Zhu Y S, Zhang B S, Liu X, et al. Unravelling the Structure of Electrocatalytically Active Fe-N Complexes in Carbon for the Oxygen Reduction Reaction[J]. Angewandte Chemie-International Edition, 2014, 53(40): 10673-10677.

[9] Ramaswamy N, Tylus U, Jia Q, et al. Activity Descriptor Identification for Oxygen Reduction on Nonprecious Electrocatalysts: Linking Surface Science to Coordination Chemistry[J]. Journal of the American Chemical Society, 2013, 135(41): 15443-15449.

[10] Zhou J G, Duchesne P N, Hu Y F, et al. Fe-N Bonding in a Carbon Nanotube-Graphene Complex for Oxygen Reduction: An XAS Study[J]. Physical Chemistry Chemical Physics, 2014, 16(30): 15787-15791.

[11] Liang W, Chen J X, Liu Y W, et al. Density-Functional-Theory Calculation Analysis of Active Sites for Four-Electron Reduction of O2 on Fe/N-Doped Graphene[J]. ACS Catalysis, 2014, 4(11): 4170-4177.

[12] Lefèvre M, Dodelet J P, Bertrand P. Molecular Oxygen Reduction in PEM Fuel Cells: Evidence for the Simultaneous Presence of Two Active Sites in Fe-Based Catalysts[J]. Journal of Physical Chemistry B, 2002, 106(34): 8705-8713.

[13] Kramm U I, Herranz J, Larouche N, et al. Structure of the Catalytic Sites in Fe/N/C-Catalysts for O2-Reduction in PEM Fuel Cells[J]. Physical Chemistry Chemical Physics, 2012, 14(33): 11673-11688.

[14] Kramm U I, Lefèvre M, Larouche N, et al. Correlations between Mass Activity and Physicochemical Properties of Fe/N/C Catalysts for the ORR in PEM Fuel Cell via 57Fe Mössbauer Spectroscopy and Other Techniques[J]. Journal of the American Chemical Society, 2014, 136(3): 978-985.

[15] Ferrandon M, Kropf A J, Myers D J, et al. Multitechnique Characterization of a Polyaniline-Iron-Carbon Oxygen Reduction Catalyst[J]. Journal of Physical Chemistry C, 2012, 116(30): 16001-16013.

[16] Zitolo A, Goellner V, Armel V, et al. Identification of Catalytic Sites for Oxygen Reduction in Iron- and Nitrogen-Doped Graphene Materials[J]. Nature Materials, 2015, 14(9): 937-944.

[17] Wang M Q, Yang W H, Wang H H, et al. Pyrolyzed Fe-N-C Composite as an Efficient Non-Precious Metal Catalyst for Oxygen Reduction Reaction in Acidic Medium[J]. ACS Catalysis, 2014, 4(11): 3928-3936.

[18] Zhang S M, Liu B, Chen S L. Synergistic Increase of Oxygen Reduction Favourable Fe-N Coordination Structures in a Ternary Hybrid of Carbon Nanospheres/Carbon Nanotubes/Graphene Sheets[J]. Physical Chemistry Chemical Physics, 2013, 15(42): 18482-18490.

[19] Wang Q, Zhou Z Y, Lai Y J, et al. Phenylenediamine-Based FeNx/C Catalyst with High Activity for Oxygen Reduction in Acid Medium and Its Active-Site Probing[J]. Journal of the American Chemical Society, 2014, 136(31): 10882-10885.

[20] Artyushkova K, Kiefer B, Halevi B, et al. Density Functional Theory Calculations of XPS Binding Energy Shift for Nitrogen-Containing Graphene-Like Structures[J]. Chemical Communications, 2013, 49(25): 2539-2541.

[21] Liu G, Li X G, Ganesan P, et al. Studies of Oxygen Reduction Reaction Active Sites and Stability of Nitrogen-Modified Carbon Composite Catalysts for PEM Fuel Cells[J]. Electrochimica Acta, 2010, 55(8): 2853-2858.

[22] Tylus U, Jia Q, Strickland K, et al. Elucidating Oxygen Reduction Active Sites in Pyrolyzed Metal-Nitrogen Coordinated Non-Precious-Metal Electrocatalyst Systems[J]. Journal of Physical Chemistry C, 2014, 118(17): 8999-9008.



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