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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Fe–N doped carbon nanotube/graphene composite: facile synthesis and superior electrocatalytic activity
TL;DR: In this paper, the authors reported the facile synthesis and superior electrocatalytic activity of an Fe-N doped nanocarbon composite of carbon nanotubes (CNTs) grown on/between graphene sheets.
Journal ArticleDOI
Engineering Favorable Morphology and Structure of Fe-N-C Oxygen-Reduction Catalysts through Tuning of Nitrogen/Carbon Precursors
TL;DR: Multiple key factors associated with the observed promotion are elucidated, including the optimal pore size distribution, highest electrochemically active surface area, presence of dominant amorphous carbon, and thick graphitic carbon layers with more pyridinic nitrogen edge sites likely bonded with active atomic iron.
Journal ArticleDOI
On the Origin of Electrocatalytic Oxygen Reduction Reaction on Electrospun Nitrogen–Carbon Species
Dongyoon Shin,Beomgyun Jeong,Bongjin Simon Mun,Hongrae Jeon,Hyun-Joon Shin,Jaiyoon Baik,Jaeyoung Lee +6 more
TL;DR: In this article, a facile approach to the synthesis of highly active Co-modified N-C catalyst and investigated the origin of ORR activity of electrospun N−C species by removing the metal with hydroxide carbon etching and acid metal leaching.
Journal ArticleDOI
Active Site Structures in Nitrogen-Doped Carbon-Supported Cobalt Catalysts for the Oxygen Reduction Reaction.
TL;DR: Control of the parameters that affect the final structure is critical to catalyst performance and, therefore, the effective development of high-performance heteroatom-doped non-noble-metal ORR catalysts.
Journal ArticleDOI
La1.5Sr0.5NiMn0.5Ru0.5O6 Double Perovskite with Enhanced ORR/OER Bifunctional Catalytic Activity
Maria Retuerto,Federico Calle-Vallejo,Laura Pascual,Gunnar Lumbeeck,María Teresa Fernández-Díaz,Mark Croft,Jagannatha Gopalakrishnan,Miguel A. Peña,Joke Hadermann,Martha Greenblatt,Sergio Rojas +10 more
TL;DR: Density functional theory calculations demonstrate that the high ORR/OER activity of LSNMR is related to the presence of active Mn Sites for the ORR- and Ru-active sites for the OER by virtue of the high symmetry of the respective reaction steps on those sites.
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.
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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.
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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.