Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > An alternative to platinum: Iron-nitrogen compounds as catalysts in graphene

Nano-island of graphene in which iron-nitrogen complexes are embedded. The FeN4 complexes (shown in orange) are catalytically active.

Image: S. Fiechter/HZB
Nano-island of graphene in which iron-nitrogen complexes are embedded. The FeN4 complexes (shown in orange) are catalytically active.

Image: S. Fiechter/HZB

Abstract:
Fuel cells convert the chemical energy stored in hydrogen (H2) into electrical energy by electrochemically "combusting" hydrogen gas with oxygen (O2) from the air into water (H2O), thereby generating electricity. As a result, future electric automobiles might be operated quite well with fuel cells instead of with heavy batteries. But for "cold" combustion of hydrogen and oxygen to function well, the anode and cathode of the fuel cell must be coated with extremely active catalysts. The problem is that the platinum-based catalysts employed for this contribute about 25 per cent of the total fuel-cell costs.

An alternative to platinum: Iron-nitrogen compounds as catalysts in graphene

Berlin, Germany | Posted on January 28th, 2016

However, iron-nitrogen complexes in graphene (known as Fe-N-C catalysts) have been achieving levels of activity comparable to Pt/C catalysts for several years already. "Systematic investigation of Fe-N-C catalysts was difficult though, since most approaches for preparing the materials lead to heterogeneous compounds. These contain various species of iron compounds such as iron carbides or nitrides besides the intended FeN4 centres", explains Sebastian Fiechter of HZB.

High density of catalytically active centres

"We had already developed a new preparation method at HZB a few years ago to produce an inexpensive catalyst material from organometallic compounds such as iron or cobalt porphyrin", reports Peter Bogdanoff, HZB. Ulrike Kramm and Iris Herrmann-Geppert improved the process for producing it as part of their doctoral studies at HZB. As a result, the metal-N-C catalysts developed at HZB held the world record for the highest density of catalytically active centres of various nitro-metallic compounds up to about 2011. However, it remained unclear as to which inorganic compounds influenced the catalytic efficiency. The team was now able to determine this.

Purification process removes interfering compounds

The highlight in the current work is a purification process (a combination of thermal treatment with a subsequent etching step) by which the proportion of metallic compounds that interfere with catalytic activity can be substantially reduced, even for catalysts that are highly heterogeneous. The interesting thing here is that the activity increases enormously! Ulrike Kramm, who has since become a junior professor at TU Darmstadt, was successful in purifying several catalysts to such an extent that all the iron present in the graphene layers was exclusively in form of complexes made of iron and four nitrogen atoms (FeN4). The scientists thereby disproved the hypothesis debated among experts by which improvement in the activity of the FeN4 centres only resulted from promoters, as they are known, such as iron nanoparticles.

Now verified: FeN4 centres provide the high catalytic efficiency even without promoters

"To check this hypothesis, we employed numerous complex measurement techniques like Mößbauer spectroscopy, electron paramagnetic resonance spectroscopy and X-ray absorption spectroscopy at BESSY II. These enabled us to precisely survey the atomic structure of the catalytic centres", Ulrike Kramm reports.

"The purification process enables us now to create catalysts having exclusively FeN4 centres. This allows us to subsequently select compounds to be added afterwards as promoters that further improve the activity level or stability of these catalysts", as Ulrike Kramm summarises her research approach at TU Darmstadt.

Sebastian Fiechter and Peter Bogdanoff are continuing their research at HZB on novel catalysts, especially in regard to hydrogen generation using sunlight. "We can also use the insights into how these metal-N-C catalysts work in our on-going development of catalysing materials for solar-based hydrogen production at HZB," says Fiechter.

Together, the research activities at HZB and TU Darmstadt could enable the development of a complete regenerative energy cycle, using solar hydrogen in low cost fuel cells, thus producing electricity without climate gas emission.

The results have now been published in the Journal of the American Chemical Society.

On an easy way to prepare Metal-Nitrogen doped carbon with exclusive presence of MeN4-type sites active for the ORR, by Ulrike I. Kramm, Iris Herrmann-Geppert, Jan Behrends, Klaus Lips, Sebastian Fiechter and Peter Bogdanoff

####

For more information, please click here

Contacts:
Prof. Dr. Sebastian Fiechter

49-308-062-42927

Copyright © Helmholtz-Zentrum Berlin für Materialien und Energie

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

RELATED JOURNAL ARTICLE:

Related News Press

Chemistry

Cambridge chemists discover simple way to build bigger molecules – one carbon at a time June 6th, 2025

News and information

INRS and ELI deepen strategic partnership to train the next generation in laser science:PhD students will benefit from international mobility and privileged access to cutting-edge infrastructure June 6th, 2025

Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025

Quantum computers simulate fundamental physics: shedding light on the building blocks of nature June 6th, 2025

A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025

Graphene/ Graphite

Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025

Possible Futures

Ben-Gurion University of the Negev researchers several steps closer to harnessing patient's own T-cells to fight off cancer June 6th, 2025

Researchers unveil a groundbreaking clay-based solution to capture carbon dioxide and combat climate change June 6th, 2025

Cambridge chemists discover simple way to build bigger molecules – one carbon at a time June 6th, 2025

A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025

Discoveries

Researchers unveil a groundbreaking clay-based solution to capture carbon dioxide and combat climate change June 6th, 2025

Cambridge chemists discover simple way to build bigger molecules – one carbon at a time June 6th, 2025

Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025

A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025

Materials/Metamaterials/Magnetoresistance

Researchers unveil a groundbreaking clay-based solution to capture carbon dioxide and combat climate change June 6th, 2025

A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025

Institute for Nanoscience hosts annual proposal planning meeting May 16th, 2025

Superconductors: Amazingly orderly disorder: A surprising effect was discovered through a collaborative effort by researchers from TU Wien and institutions in Croatia, France, Poland, Singapore, Switzerland, and the US during the investigation of a special material: the atoms are May 14th, 2025

Announcements

INRS and ELI deepen strategic partnership to train the next generation in laser science:PhD students will benefit from international mobility and privileged access to cutting-edge infrastructure June 6th, 2025

Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025

Quantum computers simulate fundamental physics: shedding light on the building blocks of nature June 6th, 2025

A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters

Cambridge chemists discover simple way to build bigger molecules – one carbon at a time June 6th, 2025

Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025

Quantum computers simulate fundamental physics: shedding light on the building blocks of nature June 6th, 2025

A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025

Energy

Portable Raman analyzer detects hydrogen leaks from a distance: Device senses tiny concentration changes of hydrogen in ambient air, offering a dependable way to detect and locate leaks in pipelines and industrial systems April 25th, 2025

KAIST researchers introduce new and improved, next-generation perovskite solar cell​ November 8th, 2024

Unveiling the power of hot carriers in plasmonic nanostructures August 16th, 2024

Groundbreaking precision in single-molecule optoelectronics August 16th, 2024

Automotive/Transportation

Portable Raman analyzer detects hydrogen leaks from a distance: Device senses tiny concentration changes of hydrogen in ambient air, offering a dependable way to detect and locate leaks in pipelines and industrial systems April 25th, 2025

Leading the charge to better batteries February 28th, 2025

Researchers are cracking the code on solid-state batteries: Using a combination of advanced imagery and ultra-thin coatings, University of Missouri researchers are working to revolutionize solid-state battery performance February 28th, 2025

Giving batteries a longer life with the Advanced Photon Source: New research uncovers a hydrogen-centered mechanism that triggers degradation in the lithium-ion batteries that power electric vehicles September 13th, 2024

Fuel Cells

Current and Future Developments in Nanomaterials and Carbon Nanotubes: Applications of Nanomaterials in Energy Storage and Electronics October 28th, 2022

The “dense” potential of nanostructured superconductors: Scientists use unconventional spark plasma sintering method to prepare highly dense superconducting bulk magnesium diboride with a high current density October 7th, 2022

New iron catalyst could – finally! – make hydrogen fuel cells affordable: Study shows the low-cost catalyst can be a viable alternative to platinum that has stymied commercialization of the eco-friendly fuel for decades because it’s so expensive July 8th, 2022

Development of high-durability single-atomic catalyst using industrial humidifier: Identification of the operating mechanism of cobalt-based single-atomic catalyst and development of a mass production process. Utilization for catalyst development in various fields including fuel May 13th, 2022

Solar/Photovoltaic

KAIST researchers introduce new and improved, next-generation perovskite solar cell​ November 8th, 2024

Groundbreaking precision in single-molecule optoelectronics August 16th, 2024

Development of zinc oxide nanopagoda array photoelectrode: photoelectrochemical water-splitting hydrogen production January 12th, 2024

Shedding light on unique conduction mechanisms in a new type of perovskite oxide November 17th, 2023

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project