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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Edge-Selectively Sulfurized Graphene Nanoplatelets as Efficient Metal-Free Electrocatalysts for Oxygen Reduction Reaction
TL;DR: The resultant edge-selectively sulfurized graphene nanoplatelets exhibit remarkable electrocatalytic activity toward ORR with better tolerance to methanol crossover/CO poisoning effects and longer-term stability than those of pristine graphite and commercial Pt/C Electrocatalysts.
Journal ArticleDOI
Poly(aryl piperidinium) membranes and ionomers for hydroxide exchange membrane fuel cells
Junhua Wang,Yun Zhao,Brian P. Setzler,Santiago Rojas-Carbonell,Chaya Ben Yehuda,Alina Amel,Miles Page,Lan Wang,Keda Hu,Lin Shi,Shimshon Gottesfeld,Bingjun Xu,Yushan Yan +12 more
TL;DR: In this article, a high-performance family of poly(aryl piperidinium) membranes was proposed for HEMFCs with high ionic conductivity, chemical stability, mechanical robustness, and selective solubility.
Journal ArticleDOI
Challenges of non-aqueous Li–O2 batteries: electrolytes, catalysts, and anodes
TL;DR: In this article, the authors provide a specific perspective on the development of non-aqueous Li-O2 batteries excluding those with aqueous, ionic liquid, hybrid, and solid-state electrolytes.
Journal ArticleDOI
Elucidating Oxygen Reduction Active Sites in Pyrolyzed Metal–Nitrogen Coordinated Non-Precious-Metal Electrocatalyst Systems
Urszula Tylus,Qingying Jia,Kara Strickland,Nagappan Ramaswamy,Alexey Serov,Plamen Atanassov,Sanjeev Mukerjee +6 more
TL;DR: Using pyrolyzed model structures of iron porphyrins, a covalent integration of the Fe–Nx sites into π-conjugated carbon basal plane modifies electron donating/withdrawing capability of the carbonaceous ligand, consequently improving ORR activity.
Journal ArticleDOI
Shape-controlled synthesis of MnO2 nanostructures with enhanced electrocatalytic activity for oxygen reduction
TL;DR: In this paper, three types of MnO2 nanostructures, viz., microsphere/nanosheet core−corona hierarchical architectures, one-dimensional (1D) nanorods, and nanotubes, have been synthesized employing a simple hydrothermal process.
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.
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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.