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
Nanoporous Graphene Enriched with Fe/Co‐N Active Sites as a Promising Oxygen Reduction Electrocatalyst for Anion Exchange Membrane Fuel Cells
Thangavelu Palaniselvam,Thangavelu Palaniselvam,Varchaswal Kashyap,Siddeswar N. Bhange,Jong-Beom Baek,Sreekumar Kurungot +5 more
TL;DR: In this article, a simple but efficient way is demonstrated for the preparation of nanoporous graphene enriched with Fe/Co-nitrogen-doped active sites (Fe/Co NpGr) as a potential electrocatalyst for the electrochemical oxygen reduction reaction (ORR) applications.
Journal ArticleDOI
The Achilles' heel of iron-based catalysts during oxygen reduction in an acidic medium
Chang Hyuck Choi,Hyung-Kyu Lim,Min Wook Chung,Gajeon Chon,Nastaran Ranjbar Sahraie,Abdulrahman Altin,Moulay Tahar Sougrati,Lorenzo Stievano,Hyun Seok Oh,Eun Soo Park,Fang Luo,Peter Strasser,Goran Dražić,Karl Johann Jakob Mayrhofer,Karl Johann Jakob Mayrhofer,Karl Johann Jakob Mayrhofer,Hyungjun Kim,Frédéric Jaouen +17 more
TL;DR: In this paper, the authors showed that FeNxCy moieties in a representative Fe-N-C catalyst are structurally stable but electrochemically unstable when exposed in an acidic medium to H2O2.
Journal ArticleDOI
Reaction Pathway for Oxygen Reduction on FeN4 Embedded Graphene.
Shyam Kattel,Guofeng Wang +1 more
TL;DR: The theoretical study suggests that nonprecious FeN4 embedded graphene could possess catalytic activity for ORR comparable to that of precious Pt catalysts.
Journal ArticleDOI
3-D Carbon Nanotube Structures Used as High Performance Catalyst for Oxygen Reduction Reaction
Wei Xiong,Feng Du,Yong Liu,Albert Perez,Michael Supp,Terizhandur S. Ramakrishnan,Liming Dai,Li Jiang +7 more
TL;DR: Characterization in conditions analogous to the operation of a polymer electrolyte membrane fuel cell show ORR taking place on the catalyst at a favorable reduction potential with a superior current density and greater rate constant.
Journal ArticleDOI
Synergistic Effect between Metal–Nitrogen–Carbon Sheets and NiO Nanoparticles for Enhanced Electrochemical Water‐Oxidation Performance
TL;DR: FeNC sheets, as the advanced supports, synergistically promote the NiO nanocatalysts to exhibit superior performance in alkaline media, which is confirmed by experimental observations and density functional theory (DFT) calculations.
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.