Highly accessible and dense surface single metal FeN4 active sites for promoting the oxygen reduction reaction

Guangbo Chen; Yun An; Shengwen Liu; Fanfei Sun; Haoyuan Qi; Haofei Wu; Yanghua He; Pan Liu; Run Shi; Jian Zhang; Agnieszka Kuc; Ute Kaiser; Tierui Zhang; Thomas Heine; Gang Wu; Xinliang Feng

doi:10.1039/d2ee00542e

Highly accessible and dense surface single metal FeN₄ active sites for promoting the oxygen reduction reaction

Guangbo Chen, Yun An, Shengwen Liu, Fanfei Sun, Haoyuan Qi, Haofei Wu, Yanghua He, Pan Liu, Run Shi, Jian Zhang, Agnieszka Kuc, Ute Kaiser, Tierui Zhang, Thomas Heine, Gang Wu, Xinliang Feng

Department of Chemistry

Research output: Contribution to journal › Article › peer-review

34 Citations (Scopus)

Abstract

Single iron atom and nitrogen-codoped carbon (Fe-N-C) electrocatalysts, which have great potential to catalyze the kinetically sluggish oxygen reduction reaction (ORR), have been recognized as the most promising alternatives to the precious metal platinum. Unfortunately, the ORR properties of the existing Fe-N-C catalysts are significantly hampered by the inferior accessibility and intrinsic activity of FeN₄ moieties. Here, we constructed densely exposed surface FeN₄ moieties on a hierarchically porous carbon (sur-FeN₄-HPC) by Fe ion anchoring and a subsequent pyrolysis strategy using the nitrogen-doped hierarchically porous carbon (NHPC) as the scaffold. The high surface area of the NHPC with abundant surface Fe anchoring sites enabled the successful fabrication of densely accessible FeN₄ active moieties (34.7 × 10¹⁹ sites g⁻¹) on sur-FeN₄-HPC. First-principles calculations further suggested that the edge effect could regulate the electronic structure of the single Fe site, hence promoting the intrinsic ORR activity of the FeN₄ moiety. As a result, the sur-FeN₄-HPC electrocatalyst exhibited excellent ORR activity in acidic media with a high half-wave potential of 0.83 V (vs. the reversible hydrogen electrode). We further examined sur-FeN₄-HPC as a cathode catalyst in proton exchange membrane fuel cells (PEMFCs). The membrane electrode assembly delivered a high current density of 24.2 mA cm⁻² at 0.9 V_iR-free (internal resistance-compensated voltage) under 1.0 bar O₂ and a maximum peak power density of 0.412 W cm⁻² under 1.0 bar air. Importantly, the catalyst demonstrated promising durability during 30 000 voltage cycles under harsh H₂ and air conditions. The PEMFC performance of sur-FeN₄-HPC outperforms those of the previously reported Fe-N-C electrocatalysts. The engineering of highly accessible and dense surface FeN₄ sites on sur-FeN₄-HPC offers a fruitful pathway for designing high-performance electrocatalysts for different electrochemical processes.

Original language	English
Pages (from-to)	2619-2628
Number of pages	10
Journal	Energy and Environmental Science
Volume	15
Issue number	6
DOIs	https://doi.org/10.1039/d2ee00542e
Publication status	Published - 2022 May 4

Bibliographical note

Funding Information:
The authors gratefully acknowledge the financial support provided by the Deutsche Forschungsgemeinschaft (COORNETs, SPP 1928 and CRC-1415: 417590517) and the EU Graphene Flagship (GrapheneCore3: 881603). Prof. J. Zhang thanks funding support from the Fundamental Research Funds for the Central Universities (310201911cx028) and the Shaanxi National Science Foundation (2020JQ-141). Y. A., A. K. and T. H. acknowledge the Centre for Information Services and High-Performance Computing (ZIH) in Dresden. G. Chen and Y. An thank the China Scholarship Council (CSC). We also acknowledge the Center for Advancing Electronics Dresden (Cfaed) and the Dresden Center for Nanoanalysis (DCN) at TU Dresden. Open Access funding provided by the Max Planck Society.

Publisher Copyright:
© 2022 The Royal Society of Chemistry.

All Science Journal Classification (ASJC) codes

Environmental Chemistry
Renewable Energy, Sustainability and the Environment
Nuclear Energy and Engineering
Pollution

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1039/d2ee00542e

Cite this

@article{4676f98b56a64a7a8483ddc722378f10,

title = "Highly accessible and dense surface single metal FeN4 active sites for promoting the oxygen reduction reaction",

abstract = "Single iron atom and nitrogen-codoped carbon (Fe-N-C) electrocatalysts, which have great potential to catalyze the kinetically sluggish oxygen reduction reaction (ORR), have been recognized as the most promising alternatives to the precious metal platinum. Unfortunately, the ORR properties of the existing Fe-N-C catalysts are significantly hampered by the inferior accessibility and intrinsic activity of FeN4 moieties. Here, we constructed densely exposed surface FeN4 moieties on a hierarchically porous carbon (sur-FeN4-HPC) by Fe ion anchoring and a subsequent pyrolysis strategy using the nitrogen-doped hierarchically porous carbon (NHPC) as the scaffold. The high surface area of the NHPC with abundant surface Fe anchoring sites enabled the successful fabrication of densely accessible FeN4 active moieties (34.7 × 1019 sites g−1) on sur-FeN4-HPC. First-principles calculations further suggested that the edge effect could regulate the electronic structure of the single Fe site, hence promoting the intrinsic ORR activity of the FeN4 moiety. As a result, the sur-FeN4-HPC electrocatalyst exhibited excellent ORR activity in acidic media with a high half-wave potential of 0.83 V (vs. the reversible hydrogen electrode). We further examined sur-FeN4-HPC as a cathode catalyst in proton exchange membrane fuel cells (PEMFCs). The membrane electrode assembly delivered a high current density of 24.2 mA cm−2 at 0.9 ViR-free (internal resistance-compensated voltage) under 1.0 bar O2 and a maximum peak power density of 0.412 W cm−2 under 1.0 bar air. Importantly, the catalyst demonstrated promising durability during 30 000 voltage cycles under harsh H2 and air conditions. The PEMFC performance of sur-FeN4-HPC outperforms those of the previously reported Fe-N-C electrocatalysts. The engineering of highly accessible and dense surface FeN4 sites on sur-FeN4-HPC offers a fruitful pathway for designing high-performance electrocatalysts for different electrochemical processes.",

author = "Guangbo Chen and Yun An and Shengwen Liu and Fanfei Sun and Haoyuan Qi and Haofei Wu and Yanghua He and Pan Liu and Run Shi and Jian Zhang and Agnieszka Kuc and Ute Kaiser and Tierui Zhang and Thomas Heine and Gang Wu and Xinliang Feng",

note = "Funding Information: The authors gratefully acknowledge the financial support provided by the Deutsche Forschungsgemeinschaft (COORNETs, SPP 1928 and CRC-1415: 417590517) and the EU Graphene Flagship (GrapheneCore3: 881603). Prof. J. Zhang thanks funding support from the Fundamental Research Funds for the Central Universities (310201911cx028) and the Shaanxi National Science Foundation (2020JQ-141). Y. A., A. K. and T. H. acknowledge the Centre for Information Services and High-Performance Computing (ZIH) in Dresden. G. Chen and Y. An thank the China Scholarship Council (CSC). We also acknowledge the Center for Advancing Electronics Dresden (Cfaed) and the Dresden Center for Nanoanalysis (DCN) at TU Dresden. Open Access funding provided by the Max Planck Society. Publisher Copyright: {\textcopyright} 2022 The Royal Society of Chemistry.",

year = "2022",

month = may,

day = "4",

doi = "10.1039/d2ee00542e",

language = "English",

volume = "15",

pages = "2619--2628",

journal = "Energy and Environmental Science",

issn = "1754-5692",

publisher = "Royal Society of Chemistry",

number = "6",

}

TY - JOUR

T1 - Highly accessible and dense surface single metal FeN4 active sites for promoting the oxygen reduction reaction

AU - Chen, Guangbo

AU - An, Yun

AU - Liu, Shengwen

AU - Sun, Fanfei

AU - Qi, Haoyuan

AU - Wu, Haofei

AU - He, Yanghua

AU - Liu, Pan

AU - Shi, Run

AU - Zhang, Jian

AU - Kuc, Agnieszka

AU - Kaiser, Ute

AU - Zhang, Tierui

AU - Heine, Thomas

AU - Wu, Gang

AU - Feng, Xinliang

N1 - Funding Information: The authors gratefully acknowledge the financial support provided by the Deutsche Forschungsgemeinschaft (COORNETs, SPP 1928 and CRC-1415: 417590517) and the EU Graphene Flagship (GrapheneCore3: 881603). Prof. J. Zhang thanks funding support from the Fundamental Research Funds for the Central Universities (310201911cx028) and the Shaanxi National Science Foundation (2020JQ-141). Y. A., A. K. and T. H. acknowledge the Centre for Information Services and High-Performance Computing (ZIH) in Dresden. G. Chen and Y. An thank the China Scholarship Council (CSC). We also acknowledge the Center for Advancing Electronics Dresden (Cfaed) and the Dresden Center for Nanoanalysis (DCN) at TU Dresden. Open Access funding provided by the Max Planck Society. Publisher Copyright: © 2022 The Royal Society of Chemistry.

PY - 2022/5/4

Y1 - 2022/5/4

N2 - Single iron atom and nitrogen-codoped carbon (Fe-N-C) electrocatalysts, which have great potential to catalyze the kinetically sluggish oxygen reduction reaction (ORR), have been recognized as the most promising alternatives to the precious metal platinum. Unfortunately, the ORR properties of the existing Fe-N-C catalysts are significantly hampered by the inferior accessibility and intrinsic activity of FeN4 moieties. Here, we constructed densely exposed surface FeN4 moieties on a hierarchically porous carbon (sur-FeN4-HPC) by Fe ion anchoring and a subsequent pyrolysis strategy using the nitrogen-doped hierarchically porous carbon (NHPC) as the scaffold. The high surface area of the NHPC with abundant surface Fe anchoring sites enabled the successful fabrication of densely accessible FeN4 active moieties (34.7 × 1019 sites g−1) on sur-FeN4-HPC. First-principles calculations further suggested that the edge effect could regulate the electronic structure of the single Fe site, hence promoting the intrinsic ORR activity of the FeN4 moiety. As a result, the sur-FeN4-HPC electrocatalyst exhibited excellent ORR activity in acidic media with a high half-wave potential of 0.83 V (vs. the reversible hydrogen electrode). We further examined sur-FeN4-HPC as a cathode catalyst in proton exchange membrane fuel cells (PEMFCs). The membrane electrode assembly delivered a high current density of 24.2 mA cm−2 at 0.9 ViR-free (internal resistance-compensated voltage) under 1.0 bar O2 and a maximum peak power density of 0.412 W cm−2 under 1.0 bar air. Importantly, the catalyst demonstrated promising durability during 30 000 voltage cycles under harsh H2 and air conditions. The PEMFC performance of sur-FeN4-HPC outperforms those of the previously reported Fe-N-C electrocatalysts. The engineering of highly accessible and dense surface FeN4 sites on sur-FeN4-HPC offers a fruitful pathway for designing high-performance electrocatalysts for different electrochemical processes.

AB - Single iron atom and nitrogen-codoped carbon (Fe-N-C) electrocatalysts, which have great potential to catalyze the kinetically sluggish oxygen reduction reaction (ORR), have been recognized as the most promising alternatives to the precious metal platinum. Unfortunately, the ORR properties of the existing Fe-N-C catalysts are significantly hampered by the inferior accessibility and intrinsic activity of FeN4 moieties. Here, we constructed densely exposed surface FeN4 moieties on a hierarchically porous carbon (sur-FeN4-HPC) by Fe ion anchoring and a subsequent pyrolysis strategy using the nitrogen-doped hierarchically porous carbon (NHPC) as the scaffold. The high surface area of the NHPC with abundant surface Fe anchoring sites enabled the successful fabrication of densely accessible FeN4 active moieties (34.7 × 1019 sites g−1) on sur-FeN4-HPC. First-principles calculations further suggested that the edge effect could regulate the electronic structure of the single Fe site, hence promoting the intrinsic ORR activity of the FeN4 moiety. As a result, the sur-FeN4-HPC electrocatalyst exhibited excellent ORR activity in acidic media with a high half-wave potential of 0.83 V (vs. the reversible hydrogen electrode). We further examined sur-FeN4-HPC as a cathode catalyst in proton exchange membrane fuel cells (PEMFCs). The membrane electrode assembly delivered a high current density of 24.2 mA cm−2 at 0.9 ViR-free (internal resistance-compensated voltage) under 1.0 bar O2 and a maximum peak power density of 0.412 W cm−2 under 1.0 bar air. Importantly, the catalyst demonstrated promising durability during 30 000 voltage cycles under harsh H2 and air conditions. The PEMFC performance of sur-FeN4-HPC outperforms those of the previously reported Fe-N-C electrocatalysts. The engineering of highly accessible and dense surface FeN4 sites on sur-FeN4-HPC offers a fruitful pathway for designing high-performance electrocatalysts for different electrochemical processes.

UR - http://www.scopus.com/inward/record.url?scp=85132970451&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85132970451&partnerID=8YFLogxK

U2 - 10.1039/d2ee00542e

DO - 10.1039/d2ee00542e

M3 - Article

AN - SCOPUS:85132970451

SN - 1754-5692

VL - 15

SP - 2619

EP - 2628

JO - Energy and Environmental Science

JF - Energy and Environmental Science

IS - 6

ER -