Identification of the optimal doping position of hetero-atoms in chalcogen-doped Fe–N–C catalysts for oxygen reduction reaction (Open Access)--颗粒学报PARTICUOLOGY

Liu, W., He, H., Liu, Q., Wan, X., & Shui, J. (2024). Identification of the optimal doping position of hetero-atoms in chalcogen-doped Fe–N–C catalysts for oxygen reduction reaction. Particuology, 89, 99-108. https://doi.org/10.1016/j.partic.2023.11.004

Identification of the optimal doping position of hetero-atoms in chalcogen-doped Fe–N–C catalysts for oxygen reduction reaction (Open Access)

Weihao Liu^a, Huanhuan He^a, Qingtao Liu^a, Xin Wan^{a b *}, Jianglan Shui ^{a c *}

a School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
b School of Space and Environment, Beihang University, Beijing, 102206, China
c Tianmushan Laboratory, Hangzhou, 310023, China

10.1016/j.partic.2023.11.004

Volume 89, June 2024, Pages 99-108

Received 18 October 2023, Revised 8 November 2023, Accepted 8 November 2023, Available online 15 November 2023, Version of Record 6 December 2023.

E-mail: wanxin@buaa.edu.cn; shuijianglan@buaa.edu.cn

Highlights

• Chalcogen atom doping improves the oxygen reduction reaction activity and stability of Fe–N–C catalysts.

• The doping positions are successfully engineered via different doping sequences.

• The first coordination shell of the center iron site is identified as the optimal doping position.

• The optimized Fe–N₃S₁/NC catalyst exhibits an outstanding peak power density of 1.08 W cm⁻² in real fuel cells.

Abstract

The excellent oxygen reduction reaction (ORR) activity of Fe–N–C catalysts in acidic media makes them potential for low-cost proton exchange membrane fuel cells. In recent years, it has been shown that heteroatoms (B, O, S, P, Cl, F, etc.) can be used as electron-withdrawing groups to modulate the planar structure and electron distribution of the Fe–N_x active sites to achieve simultaneous improvement of catalytic activity and stability. However, the optimal location of the heteroatoms remains unclear. Here, taking chalcogen heteroatoms (S and Se) as an example, we control the doping positions and investigate their effect on the ORR performance of the Fe–N–C catalysts. The first coordination shell of the iron single atom is identified as the optimal doping position. The optimized catalysts Fe–N₃S₁/NC and Fe–N₃Se₁/NC demonstrate improved activity and stability in both half cells and fuel cells. This work provides insights into the enhancement mechanism of heteroatom doping in single-atom catalysts.

Graphical abstract

Keywords

Oxygen reduction reaction; Fe–N–C catalysts; Hetero-atom doping; Doping position; Enhancement mechanism

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