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 For example, it may be that an atom is missing at a site where it normally should be found, or that a carbon atom has been replaced by a foreign atom.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 Multi-year study finds 'hotspots' of ammonia over world's major agricultural areas
17.03.2017 | University of Maryland

nachricht Diabetes Drug May Improve Bone Fat-induced Defects of Fracture Healing
17.03.2017 | Deutsches Institut für Ernährungsforschung Potsdam-Rehbrücke

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: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Pulverizing electronic waste is green, clean -- and cold

22.03.2017 | Materials Sciences

Astronomers hazard a ride in a 'drifting carousel' to understand pulsating stars

22.03.2017 | Physics and Astronomy

New gel-like coating beefs up the performance of lithium-sulfur batteries

22.03.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>