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 For example, it may be that an atom is missing at a site where it normally should be found, or that a carbon atom has been replaced by a foreign atom.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 Win-win strategies for climate and food security
02.10.2017 | International Institute for Applied Systems Analysis (IIASA)

nachricht The personality factor: How to foster the sharing of research data
06.09.2017 | ZBW – Leibniz-Informationszentrum Wirtschaft

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: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

The end of pneumonia? New vaccine offers hope

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>