Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mystery surrounding non-platinum catalysts for fuel cell technologies solved

22.01.2016

 persistent controversy in catalysts for fuel cells has just been solved by a team of researchers from the Faculty of Pure and Applied Sciences at the University of Tsukuba.

The oxygen reduction reaction is a key step in the operation of fuel cells, but depends on expensive precious metal-based catalysts. Carbon-based catalysts with added nitrogen are among the most promising alternatives to precious metals, and could allow more widespread use of fuel cell technology. However, until now, the arrangement of nitrogen and carbon that gave the catalytic effect remained a mystery, stalling efforts to develop more effective materials.


Patterning nitrogen-doped graphite to create many edges also increases the amount of pyridinic nitrogen present. Carbon atoms adjacent to pyridinic nitrogen behave as the active site for oxygen reduction, which is a key process in fuel cell technologies.

Credit: University of Tsukuba

In an article published this week in Science, a team of researchers from the University of Tsukuba identified the catalytic structure and proposed a mechanism by which the reaction works. "We knew that nitrogen-doped carbon was a good oxygen reduction catalyst, but no one was sure whether the nitrogen was pyridinic or graphitic," said corresponding author Prof. Junji Nakamura.

To solve the mystery, the team fabricated four model catalyst substrates, which simulated competing potential structures and analyzed their reaction performance. Pyridinic nitrogen, or nitrogen atoms bonded to two carbon atoms, occur mainly at the edges of the material. By patterning the substrates to change the number of edges, the team could control the presence of pyridinic nitrogen and measure how it affected the catalytic performance. These results showed that the active catalytic sites were associated with pyridinic nitrogen.

Taking the research a step further, the investigators then proposed the various stages of the reaction mechanism after finding that it was actually the carbon atom next to the nitrogen that was the active site rather than the nitrogen atom itself. As the corresponding author Prof. Nakamura noted: "Clarifying the active site and mechanism is a great step forward and will allow optimization studies to focus on driving up catalyst performance."

Media Contact

Masataka Watanabe
kohositu@un.tsukuba.ac.jp
81-298-532-039

http://un.tsukuba.ac.jp

Masataka Watanabe | EurekAlert!

More articles from Materials Sciences:

nachricht Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously
17.01.2017 | Sonderforschungsbereich 668

nachricht Manchester scientists tie the tightest knot ever achieved
13.01.2017 | University of Manchester

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

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

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>