Applied Catalysis2022，Vol.31112.DOI:10.1016/j.apcatb.2022.121366

Electrochemical transformation of Fe-N-C catalysts into iron oxides in alkaline medium and its impact on the oxygen reduction reaction activity

Mermoux, Michel Bordet, Pierre Glatzel, Pieter Ticianelli, Edson A. Jaouen, Frederic Maillard, Frederic Sgarbi, Ricardo Kumar, Kavita Saveleva, Viktoriia A. Dubau, Laetitia Chattot, Raphael Martin, Vincent
Applied Catalysis2022，Vol.31112.DOI:10.1016/j.apcatb.2022.121366
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  • NSTL
  • Elsevier

Electrochemical transformation of Fe-N-C catalysts into iron oxides in alkaline medium and its impact on the oxygen reduction reaction activity

Mermoux, Michel 1Bordet, Pierre 2Glatzel, Pieter 3Ticianelli, Edson A. 4Jaouen, Frederic 5Maillard, Frederic 1Sgarbi, Ricardo 1Kumar, Kavita 1Saveleva, Viktoriia A. 3Dubau, Laetitia 1Chattot, Raphael 3Martin, Vincent1
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作者信息

  • 1. Univ Savoie Mt Blanc
  • 2. Univ Grenoble Alpes
  • 3. ESRF European Synchrotron
  • 4. Univ Sao Paulo
  • 5. Univ Montpellier
  • 折叠

Abstract

Precious metal-free Fe-N-C catalysts efficiently electrocatalyze the oxygen reduction reaction both in acid and alkaline electrolyte. Their stability is however limited in acidic medium, but generally accepted to be much higher in alkaline electrolyte. Herein, by combining advanced electron and X-ray based techniques, we provide comprehensive evidence of a Fe dissolution/reprecipitation mechanism, which partially transforms single Fe atoms into Fe oxide nanoparticles and Fe carbide nanoparticles into Fe carbide core@Fe oxide shell nano particles, and is independent on the gas atmosphere used during the accelerated stress tests. Our work shows that Fe-N-C materials based on zero-valent Fe nanoparticles should be designed so that all Fe nanoparticles are protected by a defect-free graphite shell, for improved durability. For single atom Fe-N-C catalysts, the present study raises the question of a possible synergy between minute amount of Fe oxide nanoparticles and Fe-NxCy single-atom sites, leading to the higher apparent durability of this catalyst.

Key words

Metal-N-C catalyst/Earth-abundant metal catalyst/Fe oxide formation/Oxygen reduction reaction/Anion-exchange membrane fuel cell/DOPED POROUS CARBON/PT3CO/C NANOCRYSTALLITES/FUEL-CELLS/MEMBRANE/ELECTROCATALYSTS/DEGRADATION/PERFORMANCE/STABILITY/METAL/DURABILITY

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出版年

2022
Applied Catalysis

Applied Catalysis

ISSN：0926-3373
被引量23
参考文献量80
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