Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

More efficient all-organic catalysts in fuel cells

05.10.2012
Organic catalysts are a breakthrough in the quest for inexpensive and efficient materials for environmentally friendly production of energy in fuel cells. A new study by physicists at Umeå University in Sweden, published in ACS Nano, provides better knowledge about key processes in producing these catalysts.

The world’s needs for energy and raw materials are constantly growing, and the search for readily accessible and inexpensive material for energy applications is driving research teams all around the world.


organic catalysis

Fuel cells based on hydrogen and oxygen, for example, can convert stored chemical energy into electrical energy in an environmentally friendly way, as the byproduct is simply water. For this conversion to occur efficiently, the electrodes in the fuel cells contain various forms of catalysts.

A major problem with these catalysts is that they are currently being made of alloys of platinum, ruthenium, and other noble metals. These noble metals are not only extremely expensive but also rare and difficult to extract. The pressure to find other more readily available catalysts is therefore very strong, and hence a report in Science about three years ago that an all-organic catalyst based on nitrogen-doped carbon nanotubes could catalyze the splitting of oxygen just as effectively as platinum, evidently drew a great deal of attention.

Since then research in this field has been intensive, but yet many questions remain regarding the mechanism and efficiency of catalytic processes that occur at the defects where nitrogen atoms have replaced carbon atoms in the carbon nanotubes. A normal “ideal” carbon nanotube consists entirely of carbon atoms, but in practice most materials have defects. For example, it may be that an atom is missing at a site where it normally should be found, or that a carbon atom has been replaced by a foreign atom.
“In our case we deliberately created defects in the carbon nanotubes by replacing some of the carbon atoms with nitrogen atoms. We did this to create local centers around these defects that have an increased electron density. The increase in electron density leads to the desired catalytic properties,” says Thomas Wågberg, associate professor at the Department of Physics.

The study shows that the catalytic effect is much larger around certain types of nitrogen defects than around other types.

“We also show that it’s possible to use simple heat treatment to convert inefficient nitrogen defects into highly efficient defects,” says Thomas Wågberg.

Similar materials that the research group is studying also show great potential to catalyze other processes, such as the reverse process of splitting water into oxygen and hydrogen, which is referred to as artificial photosynthesis.

Behind the study is a research team at the Department of Physics, directed by Associate Professor Thomas Wågberg and including Tiva Sharifi, Dr. Guangzhi Hu, and Dr. Xueen Jia, with funding from, among others, the Knut and Alice Wallenberg Foundation, the Swedish Research Council, ÅForsk (Ångpanneföreningen’s Foundation for Research and Development), and the Kempe Foundation.

About the publication:
Tiva Sharifi, Guangzhi Hu, Xueen Jia, and Thomas Wagberg, Formation of Active Sites for Oxygen Reduction Reactions by Transformation of Nitrogen Functionalities in Nitrogen-Doped Carbon Nanotubes,ACS Nano DOI: 10.1021/nn302906r.
Publication online: http://pubs.acs.org/doi/pdf/10.1021/nn302906r
Reference in Science: K. Gong, F. Du, Z. Xia, M. Durstock, L. Dai, Nitrogen-Doped Carbon Nanotube Arrays with High Electrocatalytic Activity for Oxygen Reduction, Science, 323, 760 (2009).

For more information, please contact:
Thomas Wågberg, Department of Physics, Umeå University
Telephone: +46(0)90-786 59 93
E-mail: Thomas.wagberg@physics.umu.se

Ingrid Söderbergh | idw
Further information:
http://www.umu.se
http://www.teknat.umu.se/digitalAssets/104/104940_121003_organisk_katalysator.jpg

More articles from Studies and Analyses:

nachricht The Great Unknown: Risk-Taking Behavior in Adolescents
19.01.2017 | Max-Planck-Institut für Bildungsforschung

nachricht A sudden drop in outdoor temperature increases the risk of respiratory infections
11.01.2017 | University of Gothenburg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>