Journal ArticleDOI
Iron-based catalysts with improved oxygen reduction activity in polymer electrolyte fuel cells.
TLDR
In this paper, a microporous carbon-supported iron-based catalysts with active sites believed to contain iron cations coordinated by pyridinic nitrogen functionalities in the interstices of graphitic sheets within the micropores was produced.Abstract:
Iron-based catalysts for the oxygen-reduction reaction in polymer electrolyte membrane fuel cells have been poorly competitive with platinum catalysts, in part because they have a comparatively low number of active sites per unit volume. We produced microporous carbon-supported iron-based catalysts with active sites believed to contain iron cations coordinated by pyridinic nitrogen functionalities in the interstices of graphitic sheets within the micropores. We found that the greatest increase in site density was obtained when a mixture of carbon support, phenanthroline, and ferrous acetate was ball-milled and then pyrolyzed twice, first in argon, then in ammonia. The current density of a cathode made with the best iron-based electrocatalyst reported here can equal that of a platinum-based cathode with a loading of 0.4 milligram of platinum per square centimeter at a cell voltage of >/=0.9 volt.read more
Citations
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Journal ArticleDOI
X-ray photoemission spectroscopy analysis of N-containing carbon-based cathode catalysts for polymer electrolyte fuel cells
Hideharu Niwa,Masaki Kobayashi,Koji Horiba,Yoshihisa Harada,Masaharu Oshima,Kiyoyuki Terakura,Takashi Ikeda,Yuka Koshigoe,Jun-ichi Ozaki,Seizo Miyata,Shigenori Ueda,Yoshiyuki Yamashita,Hideki Yoshikawa,Keisuke Kobayashi +13 more
TL;DR: In this article, the electronic structure of three different types of N-containing carbon-based cathode catalysts for polymer electrolyte fuel cells observed by hard X-ray photoemission spectroscopy was reported.
Journal ArticleDOI
Well-elaborated, mechanochemically synthesized Fe-TPP⊂ZIF precursors (Fe-TPP = tetraphenylporphine iron) to atomically dispersed iron–nitrogen species for oxygen reduction reaction and Zn-air batteries
Wei Wei,Xiaomeng Shi,Peng Gao,Shanshan Wang,Wei Hu,Xiaoxiao Zhao,Yuanman Ni,Xiaoyan Xu,Yanqing Xu,Wensheng Yan,Hengxing Ji,Minhua Cao +11 more
TL;DR: In this paper, a new precursor of host-guest Fe-TPP and rho-ZIF (Fe-TPP = tetraphenylporphyrin iron; rho ZIF = zeolitic imidazolate framework with the rho topology) for the first time was elaborately designed and readily prepared by one-pot mechanochemical method, and then was pyrolyzed into Fe-N/C catalysts with no need of solution-based steps and post-ammonia/acid treatments, which greatly simplified the preparation procedures.
Journal ArticleDOI
Progress in nanostructured (Fe or Co)/N/C non-noble metal electrocatalysts for fuel cell oxygen reduction reaction
TL;DR: In this article, the most active non-noble metal catalysts are derived using this method and are able to deliver a kinetic volumetric current density of 450 A/cm3 at 0.8 V under fuel cell operating conditions.
Journal ArticleDOI
Oxygen Reduction Reactions of Fe-N-C Catalysts: Current Status and the Way Forward
TL;DR: In this article, a comprehensive review of the energy conversion, transformation kinetics and electron transfer of the ORR process as catalyzed by Fe-N-C catalysts is presented.
Journal ArticleDOI
2D Single-Atom Catalyst with Optimized Iron Sites Produced by Thermal Melting of Metal–Organic Frameworks for Oxygen Reduction Reaction
Dong Liu,Dong Liu,Jin-Cheng Li,Jin-Cheng Li,Shichao Ding,Zhaoyuan Lyu,Shuo Feng,Hangyu Tian,Chenxi Huyan,Mingjie Xu,Mingjie Xu,Tao Li,Dan Du,Peng Liu,Minhua Shao,Yuehe Lin +15 more
TL;DR: In this paper, a thermal melting strategy is proposed to prepare a high specific surface area of Fe-N-doped graphene nanosheets (Fe-N/GNs) with single-atom Fe-sites on the surface which are accessible to electrolytes, optimizing their utilization and improving ORR activity.
References
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Journal ArticleDOI
Activity benchmarks and requirements for Pt, Pt-alloy, and non-Pt oxygen reduction catalysts for PEMFCs
TL;DR: In this article, the authors quantified the activities and voltage loss modes for state-of-the-art MEAs (membrane electrode assemblies), specifies performance goals needed for automotive application, and provides benchmark oxygen reduction activities for state of the art platinum electrocatalysts.
Journal ArticleDOI
A class of non-precious metal composite catalysts for fuel cells
Rajesh Bashyam,Piotr Zelenay +1 more
TL;DR: The results of this study show that heteroatomic polymers can be used not only to stabilize the non-precious metal in the acidic environment of the PEFC cathode but also to generate active sites for oxygen reduction reaction.
Journal ArticleDOI
A New Fuel Cell Cathode Catalyst
TL;DR: The use of metal phthalocyanines as catalysts for the oxidation of organic compounds has been described in the literature as mentioned in this paper, and a number of these reports were tested as cathode catalysts in fuel cells.
Journal ArticleDOI
Dependence of PEM fuel cell performance on catalyst loading
TL;DR: In this paper, a determination of the cell voltage losses observed for Pt and PtRu loading reductions in H2/air and reformate/air polymer/electrolyte-membrane fuel cells (PEMFC) is presented.
Journal ArticleDOI
Heat-treated polyacrylonitrile-based catalysts for oxygen electroreduction
TL;DR: In this paper, a polyacrylonitrile (PAN) mixed with Co(II) or Fe(2) salts and high-area carbon and then heat treated, has been found to yield very promising catalysts for O2 reduction in concentrated alkaline and acid solutions.