Encapsulated iron-based oxygen reduction electrocatalysts by high pressure pyrolysis

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Non-precious metal catalysts (NPMCs) are candidate materials to replace platinum for proton exchange membrane fuel cells (PEMFCs). Herein we reported a type of iron-based NPMCs prepared by high pressure pyrolysis for the oxygen reduction reaction (ORR) in acidic media. The catalysts are in form of carbon microspheres in a sub-microscale consisting of iron-containing nanoparticles encapsulated by graphitic layers. By tailoring temperatures and duration of pyrolysis, the best ORR catalyst was achieved at 700 degrees C and 75 min, which exhibits an onset potential of 0.85 V at 0.1 mA cm(-2) and a half-wave potential of 0.72 V in acid media. After 10,000 potential cycles, only 25 mV shift of half-wave potential is observed showing excellent stability. An analogue material prepared from nitrogen-free precursors shows significant electrochemical activity though it is much lower than that from the nitrogen containing precursors and can be improved by post treatment in ammonia. These results indicate the contribution to the catalysis from surface nitrogen functionalities and encapsulated metal-containing nanoparticles. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Original languageEnglish
JournalInternational Journal of Hydrogen Energy
Volume42
Issue number36
Pages (from-to)22887-22896
ISSN0360-3199
DOIs
Publication statusPublished - 2017

Keywords

  • Non-precious metal catalysts
  • Oxygen reduction reaction
  • High-pressure pyrolysis
  • Encapsulated structure
  • Fuel cells

Cite this

@article{e46ebe64b6164ba38a0a2492af092de5,
title = "Encapsulated iron-based oxygen reduction electrocatalysts by high pressure pyrolysis",
abstract = "Non-precious metal catalysts (NPMCs) are candidate materials to replace platinum for proton exchange membrane fuel cells (PEMFCs). Herein we reported a type of iron-based NPMCs prepared by high pressure pyrolysis for the oxygen reduction reaction (ORR) in acidic media. The catalysts are in form of carbon microspheres in a sub-microscale consisting of iron-containing nanoparticles encapsulated by graphitic layers. By tailoring temperatures and duration of pyrolysis, the best ORR catalyst was achieved at 700 degrees C and 75 min, which exhibits an onset potential of 0.85 V at 0.1 mA cm(-2) and a half-wave potential of 0.72 V in acid media. After 10,000 potential cycles, only 25 mV shift of half-wave potential is observed showing excellent stability. An analogue material prepared from nitrogen-free precursors shows significant electrochemical activity though it is much lower than that from the nitrogen containing precursors and can be improved by post treatment in ammonia. These results indicate the contribution to the catalysis from surface nitrogen functionalities and encapsulated metal-containing nanoparticles. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.",
keywords = "Non-precious metal catalysts, Oxygen reduction reaction, High-pressure pyrolysis, Encapsulated structure, Fuel cells",
author = "Lijie Zhong and Yang Hu and Cleemann, {Lars Nilausen} and Chao Pan and Jakob Svaerke and Jensen, {Jens Oluf} and Qingfeng Li",
year = "2017",
doi = "10.1016/j.ijhydene.2017.07.093",
language = "English",
volume = "42",
pages = "22887--22896",
journal = "International Journal of Hydrogen Energy",
issn = "0360-3199",
publisher = "Elsevier",
number = "36",

}

Encapsulated iron-based oxygen reduction electrocatalysts by high pressure pyrolysis. / Zhong, Lijie; Hu, Yang; Cleemann, Lars Nilausen; Pan, Chao; Svaerke, Jakob; Jensen, Jens Oluf; Li, Qingfeng.

In: International Journal of Hydrogen Energy, Vol. 42, No. 36, 2017, p. 22887-22896.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Encapsulated iron-based oxygen reduction electrocatalysts by high pressure pyrolysis

AU - Zhong, Lijie

AU - Hu, Yang

AU - Cleemann, Lars Nilausen

AU - Pan, Chao

AU - Svaerke, Jakob

AU - Jensen, Jens Oluf

AU - Li, Qingfeng

PY - 2017

Y1 - 2017

N2 - Non-precious metal catalysts (NPMCs) are candidate materials to replace platinum for proton exchange membrane fuel cells (PEMFCs). Herein we reported a type of iron-based NPMCs prepared by high pressure pyrolysis for the oxygen reduction reaction (ORR) in acidic media. The catalysts are in form of carbon microspheres in a sub-microscale consisting of iron-containing nanoparticles encapsulated by graphitic layers. By tailoring temperatures and duration of pyrolysis, the best ORR catalyst was achieved at 700 degrees C and 75 min, which exhibits an onset potential of 0.85 V at 0.1 mA cm(-2) and a half-wave potential of 0.72 V in acid media. After 10,000 potential cycles, only 25 mV shift of half-wave potential is observed showing excellent stability. An analogue material prepared from nitrogen-free precursors shows significant electrochemical activity though it is much lower than that from the nitrogen containing precursors and can be improved by post treatment in ammonia. These results indicate the contribution to the catalysis from surface nitrogen functionalities and encapsulated metal-containing nanoparticles. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

AB - Non-precious metal catalysts (NPMCs) are candidate materials to replace platinum for proton exchange membrane fuel cells (PEMFCs). Herein we reported a type of iron-based NPMCs prepared by high pressure pyrolysis for the oxygen reduction reaction (ORR) in acidic media. The catalysts are in form of carbon microspheres in a sub-microscale consisting of iron-containing nanoparticles encapsulated by graphitic layers. By tailoring temperatures and duration of pyrolysis, the best ORR catalyst was achieved at 700 degrees C and 75 min, which exhibits an onset potential of 0.85 V at 0.1 mA cm(-2) and a half-wave potential of 0.72 V in acid media. After 10,000 potential cycles, only 25 mV shift of half-wave potential is observed showing excellent stability. An analogue material prepared from nitrogen-free precursors shows significant electrochemical activity though it is much lower than that from the nitrogen containing precursors and can be improved by post treatment in ammonia. These results indicate the contribution to the catalysis from surface nitrogen functionalities and encapsulated metal-containing nanoparticles. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

KW - Non-precious metal catalysts

KW - Oxygen reduction reaction

KW - High-pressure pyrolysis

KW - Encapsulated structure

KW - Fuel cells

U2 - 10.1016/j.ijhydene.2017.07.093

DO - 10.1016/j.ijhydene.2017.07.093

M3 - Journal article

VL - 42

SP - 22887

EP - 22896

JO - International Journal of Hydrogen Energy

JF - International Journal of Hydrogen Energy

SN - 0360-3199

IS - 36

ER -