Hierarchically Porous Carbons with Highly Curved Surfaces for Hosting Single Metal FeN4 Sites as Outstanding Oxygen Reduction Catalysts

Guangbo Chen; Ruihu Lu; Chenzhao Li; Jianmin Yu; Xiaodong Li; Lingmei Ni; Qi Zhang; Guangqi Zhu; Shengwen Liu; Jiaxu Zhang; Ulrike I Kramm; Yan Zhao; Gang Wu; Jian Xie; Xinliang Feng

doi:10.1002/adma.202300907

Hierarchically Porous Carbons with Highly Curved Surfaces for Hosting Single Metal FeN₄ Sites as Outstanding Oxygen Reduction Catalysts

Adv Mater. 2023 Aug;35(32):e2300907. doi: 10.1002/adma.202300907. Epub 2023 Jun 29.

Authors

Guangbo Chen¹, Ruihu Lu², Chenzhao Li^{3

4}, Jianmin Yu⁵, Xiaodong Li^{1

6}, Lingmei Ni⁷, Qi Zhang³, Guangqi Zhu³, Shengwen Liu⁸, Jiaxu Zhang¹, Ulrike I Kramm⁷, Yan Zhao², Gang Wu⁸, Jian Xie³, Xinliang Feng^{1

6}

Affiliations

¹ Center for Advancing Electronics Dresden (Cfaed) and Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, 01062, Dresden, Germany.
² State Key Laboratory of Silicate Materials for Architectures, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, 430070, P. R. China.
³ Department of Mechanical and Energy Engineering, Purdue School of Engineering and Technology, Indiana University-Purdue University, Indianapolis, IN, 46202, USA.
⁴ School of Mechanical Engineering, Purdue University, West Lafyette, IN, 47907, USA.
⁵ Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
⁶ Department of Synthetic Materials and Functional Devices, Max Planck Institute of Microstructure Physics, D-06120, Halle (Saale), Germany.
⁷ Department of Chemistry, Eduard-Zintl Insitute of Physical and Inorganic Chemistry, TU Darmstadt, D-64287, Darmstadt, Germany.
⁸ Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, NY, 14260, USA.

PMID: 37132284
DOI: 10.1002/adma.202300907

Abstract

Iron-nitrogen-carbon (FeNC) materials have emerged as a promising alternative to platinum-group metals for catalyzing the oxygen reduction reaction (ORR) in proton-exchange-membrane fuel cells. However, their low intrinsic activity and stability are major impediments. Herein, an FeN-C electrocatalyst with dense FeN₄ sites on hierarchically porous carbons with highly curved surfaces (denoted as FeN₄ -hcC) is reported. The FeN₄ -hcC catalyst displays exceptional ORR activity in acidic media, with a high half-wave potential of 0.85 V (versus reversible hydrogen electrode) in 0.5 m H₂ SO₄ . When integrated into a membrane electrode assembly, the corresponding cathode displays a high maximum peak power density of 0.592 W cm^-2 and demonstrates operating durability over 30 000 cycles under harsh H₂ /air conditions, outperforming previously reported Fe-NC electrocatalysts. These experimental and theoretical studies suggest that the curved carbon support fine-tunes the local coordination environment, lowers the energies of the Fe d-band centers, and inhibits the adsorption of oxygenated species, which can enhance the ORR activity and stability. This work provides new insight into the carbon nanostructure-activity correlation for ORR catalysis. It also offers a new approach to designing advanced single-metal-site catalysts for energy-conversion applications.

Keywords: Fe-N-C catalysts; carbon curvature; fuel cells; hierarchically porous carbons; oxygen reduction reaction.

Abstract

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