Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Giving platinum catalysts a golden boost for fuel cells

29.03.2007
Platinum might outweigh gold in the jewelry market, but as part of an ongoing effort to produce efficient and affordable fuel cells, scientists at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory are studying how gold atoms might enhance the value of the pricier metal.

Specifically, they're looking for ways to use gold to prevent the destruction of platinum in the chemical reactions that take place in fuel cells. Brookhaven chemist Radoslav Adzic will describe this research during the 233rd National Meeting of the American Chemical Society at 2 p.m. Central Time (3 p.m. Eastern Time) on Tuesday, March 27, 2007, in room S405A, Level 4, at McCormick Place South, Chicago, Illinois.

Platinum is the most efficient electrocatalyst for accelerating chemical reactions in fuel cells. However, in reactions during the stop-and-go driving of a fuel-cell-powered electric car, the platinum dissolves. In accelerated tests, as much as 45 percent of the catalyst can be lost during five days. "Platinum is by far the best single component catalyst for the oxygen reduction reaction, and we have to find a way to protect it," Adzic said. Under lab conditions that imitate the environment of a fuel cell, Adzic and a team of Brookhaven researchers, including Junliang Zhang, Kotaro Sasaki, and Eli Sutter, added gold clusters to a platinum electrocatalyst, which kept it intact during an accelerated stability test that simulates stop-and-go driving in an electric car.

The details: A fuel cell converts hydrogen and oxygen into water and, as part of the process, produces electricity. Hydrogen is oxidized at the device's anode (the terminal where current flows in) when electrons are released and hydrogen ions are formed; the released electrons supply current for an electric motor. These electrons flow to the cathode (the terminal where current flows out) to reduce oxygen, and in a reaction with hydrogen ions, water, the only byproduct of a fuel cell reaction, is produced. Platinum electrocatalysts are used to speed up the oxidation and reduction reactions involved in this process, but as a result, they, too, are oxidized (lose electrons) and dissolve.

In the unique method used at Brookhaven, researchers place gold on carbon-supported platinum nanoparticles by displacing a single layer of copper and subject it to several sweeps of voltage. The copper is needed to reduce the charged gold particles to neutral atoms; it then conveniently forms a monolayer of platinum by an adsorption process, the binding of molecules or particles to a surface. Using x-rays as probes at Brookhaven's National Synchrotron Light Source, a scanning transmission microscope at Brookhaven's Center for Functional Nanomaterials, and electrochemical techniques in the laboratory, the scientists can show that less platinum is oxidized with this method. As predicted, during laboratory testing, the platinum electrocatalyst remains stable when under conditions mimicking stop-and-go driving conditions. Next, researchers will test the catalyst in real fuel cells at the DOE's Los Alamos National Laboratory in New Mexico.

"The very promising properties of fuel cells have been known for many decades," Adzic said. "But it's only now that we can look at the activities and qualities of the catalysts and find something stable enough to be used in cars or residential applications."

Karen McNulty Walsh | EurekAlert!
Further information:
http://www.bnl.gov

Further reports about: Adzic Brookhaven Fuel Platinum catalyst electrocatalyst

More articles from Life Sciences:

nachricht Ambush in a petri dish
24.11.2017 | Friedrich-Schiller-Universität Jena

nachricht Meadows beat out shrubs when it comes to storing carbon
23.11.2017 | Norwegian University of Science and Technology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New proton record: Researchers measure magnetic moment with greatest possible precision

High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons

The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

IceCube experiment finds Earth can block high-energy particles from nuclear reactions

24.11.2017 | Physics and Astronomy

A 'half-hearted' solution to one-sided heart failure

24.11.2017 | Health and Medicine

Heidelberg Researchers Study Unique Underwater Stalactites

24.11.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>