Fe3C-based oxygen reduction catalysts: synthesis, hollow spherical structures and applications in fuel cells

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

We present a detailed study of a novel Fe3C-based spherical catalyst with respect to synthetic parameters, nanostructure formation, ORR active sites and fuel cell demonstration. The catalyst is synthesized by high temperature autoclave pyrolysis using decomposing precursors. Below 500 °C, melamine-rich microspheres are first developed with uniformly dispersed amorphous Fe species. During the following pyrolysis at temperatures from 600 to 660 °C, a small amount of Fe3C phase with possible Fe–Nx/Cactive sites are formed, however, with moderate catalytic activity, likely limited by the low conductivity of the catalyst. At high pyrolytic temperatures of 700–800 °C, simultaneous formation of Fe3Cnanoparticles and encasing graphitic layers occur within the morphological confinement of the microspheres. With negligible surface nitrogen or iron functionality, the thus-obtained catalysts exhibit superior ORR activity and stability. A new ORR active phase of Fe3C nanoparticles encapsulated by thin graphitic layers is proposed. The activity and durability of the catalysts are demonstrated in both Nafion-based low temperature and acid doped polybenzimidazole-based high temperature proton exchange membrane fuel cells.
Original languageEnglish
JournalJournal of Materials Chemistry A
Volume3
Pages (from-to)1752-1760
ISSN2050-7488
DOIs
Publication statusPublished - 2015

Cite this

@article{998371c903b140b2982a3237ad1f94a6,
title = "Fe3C-based oxygen reduction catalysts: synthesis, hollow spherical structures and applications in fuel cells",
abstract = "We present a detailed study of a novel Fe3C-based spherical catalyst with respect to synthetic parameters, nanostructure formation, ORR active sites and fuel cell demonstration. The catalyst is synthesized by high temperature autoclave pyrolysis using decomposing precursors. Below 500 °C, melamine-rich microspheres are first developed with uniformly dispersed amorphous Fe species. During the following pyrolysis at temperatures from 600 to 660 °C, a small amount of Fe3C phase with possible Fe–Nx/Cactive sites are formed, however, with moderate catalytic activity, likely limited by the low conductivity of the catalyst. At high pyrolytic temperatures of 700–800 °C, simultaneous formation of Fe3Cnanoparticles and encasing graphitic layers occur within the morphological confinement of the microspheres. With negligible surface nitrogen or iron functionality, the thus-obtained catalysts exhibit superior ORR activity and stability. A new ORR active phase of Fe3C nanoparticles encapsulated by thin graphitic layers is proposed. The activity and durability of the catalysts are demonstrated in both Nafion-based low temperature and acid doped polybenzimidazole-based high temperature proton exchange membrane fuel cells.",
author = "Yang Hu and Jensen, {Jens Oluf} and Wei Zhang and Fernandez, {Santiago Martin} and Regis Chenitz and Chao Pan and Wei Xing and Bjerrum, {Niels J.} and Qingfeng Li",
year = "2015",
doi = "10.1039/c4ta03986f",
language = "English",
volume = "3",
pages = "1752--1760",
journal = "Journal of Materials Chemistry A",
issn = "2050-7488",
publisher = "RSC Publications",

}

Fe3C-based oxygen reduction catalysts: synthesis, hollow spherical structures and applications in fuel cells. / Hu, Yang; Jensen, Jens Oluf; Zhang, Wei; Fernandez, Santiago Martin; Chenitz, Regis ; Pan, Chao; Xing, Wei; Bjerrum, Niels J.; Li, Qingfeng.

In: Journal of Materials Chemistry A, Vol. 3, 2015, p. 1752-1760.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Fe3C-based oxygen reduction catalysts: synthesis, hollow spherical structures and applications in fuel cells

AU - Hu, Yang

AU - Jensen, Jens Oluf

AU - Zhang, Wei

AU - Fernandez, Santiago Martin

AU - Chenitz, Regis

AU - Pan, Chao

AU - Xing, Wei

AU - Bjerrum, Niels J.

AU - Li, Qingfeng

PY - 2015

Y1 - 2015

N2 - We present a detailed study of a novel Fe3C-based spherical catalyst with respect to synthetic parameters, nanostructure formation, ORR active sites and fuel cell demonstration. The catalyst is synthesized by high temperature autoclave pyrolysis using decomposing precursors. Below 500 °C, melamine-rich microspheres are first developed with uniformly dispersed amorphous Fe species. During the following pyrolysis at temperatures from 600 to 660 °C, a small amount of Fe3C phase with possible Fe–Nx/Cactive sites are formed, however, with moderate catalytic activity, likely limited by the low conductivity of the catalyst. At high pyrolytic temperatures of 700–800 °C, simultaneous formation of Fe3Cnanoparticles and encasing graphitic layers occur within the morphological confinement of the microspheres. With negligible surface nitrogen or iron functionality, the thus-obtained catalysts exhibit superior ORR activity and stability. A new ORR active phase of Fe3C nanoparticles encapsulated by thin graphitic layers is proposed. The activity and durability of the catalysts are demonstrated in both Nafion-based low temperature and acid doped polybenzimidazole-based high temperature proton exchange membrane fuel cells.

AB - We present a detailed study of a novel Fe3C-based spherical catalyst with respect to synthetic parameters, nanostructure formation, ORR active sites and fuel cell demonstration. The catalyst is synthesized by high temperature autoclave pyrolysis using decomposing precursors. Below 500 °C, melamine-rich microspheres are first developed with uniformly dispersed amorphous Fe species. During the following pyrolysis at temperatures from 600 to 660 °C, a small amount of Fe3C phase with possible Fe–Nx/Cactive sites are formed, however, with moderate catalytic activity, likely limited by the low conductivity of the catalyst. At high pyrolytic temperatures of 700–800 °C, simultaneous formation of Fe3Cnanoparticles and encasing graphitic layers occur within the morphological confinement of the microspheres. With negligible surface nitrogen or iron functionality, the thus-obtained catalysts exhibit superior ORR activity and stability. A new ORR active phase of Fe3C nanoparticles encapsulated by thin graphitic layers is proposed. The activity and durability of the catalysts are demonstrated in both Nafion-based low temperature and acid doped polybenzimidazole-based high temperature proton exchange membrane fuel cells.

U2 - 10.1039/c4ta03986f

DO - 10.1039/c4ta03986f

M3 - Journal article

VL - 3

SP - 1752

EP - 1760

JO - Journal of Materials Chemistry A

JF - Journal of Materials Chemistry A

SN - 2050-7488

ER -