Fe-loaded S, N co-doped carbon catalyst for oxygen reduction reaction with enhanced electrocatalytic activity and durability

Abstract

Heteroatom-doped carbon is considered a promising alternative to commercial Pt/C as an efficient catalyst for the oxygen reduction reaction (ORR). This study presents the synthesis of iron-loaded, sulfur and nitrogen co-doped carbon (Fe/SNC) via in situ incorporation of 2-aminothiazole molecules into zeolitic imidazolate framework-8 (ZIF-8) through coordination between metal ions and organic ligands. Sulfur and nitrogen doping in carbon supports effectively modulates the electronic structure of the catalyst, increases the Brunauer–Emmett–Teller surface area, and exposes more Fe–N_x active centers. Fe-loaded, S and N co-doped carbon with Fe/S molar ratio of 1:10 (Fe/SNC-10) exhibits a half-wave potential of 0.902 V vs. RHE. After 5000 cycles of cyclic voltammetry, its half-wave potential decreases by only 20 mV vs. RHE, indicating excellent stability. Due to sulfur’s lower electronegativity, the electronic structure of the Fe–N_x active center is modulated. Additionally, the larger atomic radius of sulfur introduces defects into the carbon support. As a result, Fe/SNC-10 demonstrates superior ORR activity and stability in alkaline solution compared with Fe-loaded N-doped carbon (Fe/NC). Furthermore, the zinc–air battery assembled with the Fe/SNC-10 catalyst shows enhanced performance relative to those assembled with Fe/NC and Pt/C catalysts. This work offers a novel design strategy for advanced energy storage and conversion applications.

Keywords

zinc–air batteries / oxygen reduction reaction / iron-loaded nitrogen-doped carbon / sulfur-doping

References

[1] Bian JJ, Cheng XP, Meng XY, et al. . Nitrogen-doped NiCo₂O₄ microsphere as an efficient catalyst for flexible rechargeable zinc–air batteries and self-charging power system. ACS Appl. Energy Mater., 2019, 2(3): 2296.

[2] Bian JJ, Li ZP, Li NW, Sun CW. Oxygen deficient LaMn_0.75Co_0.25O_3−δ nanofibers as an efficient electrocatalyst for oxygen evolution reaction and zinc–air batteries. Inorg. Chem., 2019, 58(12): 8208.

[3] Wu SW, Jiang S, Liu SQ, et al. . Single Cu–N₄ sites enable atomic Fe clusters with high-performance oxygen reduction reactions. Energy Environ. Sci., 2023, 16(8): 3576.

[4] Liu SW, Li CZ, Zachman MJ, et al. . Atomically dispersed iron sites with a nitrogen–carbon coating as highly active and durable oxygen reduction catalysts for fuel cells. Nat. Energy, 2022, 7(7): 652.

[5] Bian JJ, Su R, Yao Y, et al. . Mg doped perovskite LaNiO₃ nanofibers as an efficient bifunctional catalyst for rechargeable zinc–air batteries. ACS Appl. Energy Mater., 2019, 2(1): 923.

[6] S.Y. Zhao, T. Liu, Y.W. Dai, et al., Pt/C as a bifunctional ORR/iodide oxidation reaction (IOR) catalyst for Zn–air batteries with unprecedentedly high energy efficiency of 76.5%, Appl. Catal. B Environ., 320(2023), art. No. 121992.

[7] Li SW, Liu JJ, Yin Z, et al. . Impact of the coordination environment on atomically dispersed Pt catalysts for oxygen reduction reaction. ACS Catal., 2020, 10(1): 907.

[8] Zhu XF, Tan X, Wu KH, et al. . Intrinsic ORR activity enhancement of Pt atomic sites by engineering the d-band center via local coordination tuning. Angew. Chem. Int. Ed., 2021, 60(40): 21911.

[9] X.Y. Meng, J.X. Han, L. Lu, G.R. Qiu, Z.L. Wang, and C.W. Sun, Fe²⁺-doped layered double (Ni, Fe) hydroxides as efficient electrocatalysts for water splitting and self-powered electrochemical systems, Small, 15(2019), No. 41, art. No. 1902551.

[10] Chen JK, Zhuang YY, Qiao YX, Zhang Y, Yuan AH, Zhou H. Co/Co₇Fe₃ heterostructures with controllable alloying degree on carbon spheres as bifunctional electrocatalyst for rechargeable zinc–air batteries. Int. J. Miner. Metall. Mater., 2025, 32(2): 476.

[11] Zeng YC, Li CZ, Li BY, et al. . Tuning the thermal activation atmosphere breaks the activity–stability trade-off of Fe–N–C oxygen reduction fuel cell catalysts. Nat. Catal., 2023, 6(12): 1215.

[12] Yuan JS, Zhang Y, Zhang XY, Zhang JJ, Zhang SG. N-doped graphene quantum dot-decorated N-TiO₂/P-doped porous hollow g-C₃N₄ nanotube composite photocatalysts for antibiotic photodegradation and H₂ production. Int. J. Miner. Metall. Mater., 2024, 31(1): 165.

[13] Sun JC, Guan JD, Zhou SQ, et al. . Improving the electrocatalytic activity of Fe, N co-doped biochar for polysulfide by regulation of N–C and Fe–N–C electronic configurations. Int. J. Miner. Metall. Mater., 2023, 30(12): 2421.

[14] M.X. Shen, J. Liu, J. Li, et al., Breaking the N-limitation with N-enriched porous submicron carbon spheres anchored Fe single-atom catalyst for superior oxygen reduction reaction and Zn–air batteries, Energy Storage Mater., 59(2023), art. No. 102790.

[15] W.Y. Ding, H.F. Zhu, L. Lu, J.D. Zhang, H.Q. Yu, and H. Zhao, Three-dimensional layered Fe–N/C catalysts built by electrospinning and the comparison of different active species on oxygen reduction reaction performance, J. Alloy. Compd., 848(2020), art. No. 156605.

[16] T.R. Zhang, J.J. Bian, Y.Q. Zhu, and C.W. Sun, FeCo nanoparticles encapsulated in N-doped carbon nanotubes coupled with layered double (Co, Fe) hydroxide as an efficient bifunctional catalyst for rechargeable zinc–air batteries, Small, 17(2021), No. 44, art. No. 2103737.

[17] Wang YC, Lai YJ, Song L, 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, 54(34): 9907.

[18] S.Y. Chen, X.Q. Li, C.W. Kao, et al., Unveiling the proton-feeding effect in sulfur-doped Fe–N–C single-atom catalyst for enhanced CO₂ electroreduction, Angew. Chem. Int. Ed., 61(2022), No. 32, art. No. e202206233.

[19] Hu K, Tao L, Liu DD, Huo J, Wang SY. Sulfur-doped Fe/N/C nanosheets as highly efficient electrocatalysts for oxygen reduction reaction. ACS Appl. Mater. Interfaces, 2016, 8(30): 19379.

[20] Maouche C, Yang J, Al-Hilfi SH, Tao XF, Zhou YZ. Sulfur-doped Fe–N–C nanomaterials as catalysts for the oxygen reduction reaction in acidic medium. ACS Appl. Nano Mater., 2022, 5(3): 4397.

[21] Shen HJ, Gracia-Espino E, Ma JY, 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, 56(44): 13800.

[22] Q.H. Li, W.X. Chen, H. Xiao, et al., Fe isolated single atoms on S, N codoped carbon by copolymer pyrolysis strategy for highly efficient oxygen reduction reaction, Adv. Mater., 30(2018), No. 25, art. No. 1800588.

[23] Wang K, Zhang XR, Xiang X, et al. . In situ S-doping strategy of promoting iron coordinated by nitrogen-doped carbon nanosheets for efficient oxygen reduction reaction. ACS Appl. Mater. Interfaces, 2022, 14(41): 46548.

[24] W.J. Zhai, S.H. Huang, C.B. Lu, et al., Simultaneously integrate iron single atom and nanocluster triggered tandem effect for boosting oxygen electroreduction, Small, 18(2022), No. 15, art. No. 2107225.

[25] J.Y. Wang, T.A. Zhang, S.Z. He, and C.W. Sun, FeCo₅/Nitrogen doped carbon as an efficient bifunctional oxygen electrocatalyst for Zn–air batteries, J. Electroanal. Chem., 965(2024), art. No. 118369.

[26] Y.L. Gao, T.R. Zhang, Y.Z. Mao, J.Y. Wang, and C.W. Sun, Highly efficient bifunctional layered triple Co, Fe, Ru hydroxides and oxides composite electrocatalysts for zinc–air batteries, J. Electroanal. Chem., 935(2023), art. No. 117315.

[27] He SZ, Wang JY, Sun CW. Boosted electrocatalytic activity and durability of Cu–Fe/N–C by modulating the interfacial composition and electronic structure for efficient oxygen reduction reaction. J. Colloid Interface Sci., 2025, 677: 771.

[28] Li HX, He HB, Jiang TN, et al. . Preparation of Co/S co-doped carbon catalysts for excellent methylene blue degradation. Int. J. Miner. Metall. Mater., 2025, 32(1): 169.

[29] He N, Sun YM, Chen XY, Wang JQ, Liang GJ, Mo FN. Design of S, N-codoped Co–Fe dual-atom sites for efficient alkaline oxygen reduction. J. Mater. Chem. A, 2024, 12(17): 10101.

[30] Y. Chen, J. Rong, J. Wu, et al., MOF-derived S, N co-doped porous carbon matrix with single Fe atoms and CoS_x nanoparticles dual-sites for enhanced oxygen reduction, Chem. Eng. J., 502(2024), art. No. 158080.

[31] Zhou Y, Yu YN, Ma DS, et al. . Atomic Fe dispersed hierarchical mesoporous Fe–N–C nanostructures for an efficient oxygen reduction reaction. ACS Catal., 2021, 11(1): 74.

[32] Ma LT, Chen SM, Pei ZX, et al. . Single-site active iron-based bifunctional oxygen catalyst for a compressible and rechargeable zinc–air battery. ACS Nano, 2018, 12(2): 1949.

[33] C. Liang, X. Han, T.Y. Zhang, et al., Cu nanoclusters accelerate the rate-determining step of oxygen reduction on Fe–N–C in all pH range, Adv. Energy Mater., 14(2024), No. 14, art. No. 2303935.

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