Energy News  





. Brookhaven Lab Scientists Stabilize Platinum Electrocatalysts For Use In Fuel Cells

File image of a platinum electrocatalyst.
by Staff Writers
Upton NY (SPX) Jan 16, 2007
Platinum is the most efficient electrocatalyst for accelerating chemical reactions in fuel cells for electric vehicles. In reactions during the stop-and-go driving of an electric car, however, the platinum dissolves, which reduces its efficiency as a catalyst. This is a major impediment for vehicle-application of fuel cells.

Now, scientists at the U.S. Department of Energy's Brookhaven National Laboratory have overcome this problem. Under lab conditions that imitate the environment of a fuel cell, the researchers added gold clusters to the platinum electrocatalyst, which kept it intact during an accelerated stability test. This test is conducted under conditions similar to those encountered in stop-and-go driving in an electric car. The research is reported in the January 12, 2007, edition of the journal Science.

Brookhaven's Chemistry Department researchers Junliang Zhang, Kotaro Sasaki, and Radoslav Adzic, along with Eli Sutter from Brookhaven's Center for Functional Nanomaterials, authored the research paper.

"Fuel cells are expected to become a major source of clean energy, with particularly important applications in transportation," said coauthor Radoslav Adzic. "Despite many advances, however, existing fuel-cell technology still has drawbacks, including loss of platinum cathode electrocatalysts, which can be as much as 45 percent over five days, as shown in our accelerated stability test under potential cycling conditions.

Using a new technique that we developed to deposit gold atoms on platinum, our team was able to show promise in helping to resolve this problem. The next step is to duplicate results in real fuel cells."

A hydrogen-oxygen fuel cell converts hydrogen and oxygen into water and, as part of the process, produces electricity. Platinum electrocatalysts speed up oxidation and reduction reactions. Hydrogen is oxidized when electrons are released and hydrogen ions are formed; the released electrons supply current for an electric motor. Oxygen is reduced by gaining electrons, and in reaction with hydrogen ions, water, the only byproduct of a fuel cell reaction, is produced.

In the unique method developed at Brookhaven, the researchers displaced a single layer of copper with gold on carbon-supported platinum nanoparticles. After being subjected to several sweeps of 1.2 volts, the gold monolayer transformed into three-dimensional clusters. 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 were able to verify the reduced oxidation of platinum and to determine the structure of the resulting platinum electrocatalyst with gold clusters, which helped them to gain an understanding of the effects of the gold clusters.

In the Brookhaven experiment, the platinum electrocatalyst remained stable with potential cycling between 0.6 and 1.1 volts in over 30,000 oxidation-reduction cycles, imitating the conditions of stop-and-go driving. "The gold clusters protected the platinum from being oxidized," Adzic said. "Our team's research raises promising possibilities for synthesizing improved platinum-based catalysts and for stabilizing platinum and platinum-group metals under cycling oxidation/reduction conditions."

Community
Email This Article
Comment On This Article

Related Links
DOE/Brookhaven National Laboratory
Car Technology at SpaceMart.com
Powering The World in the 21st Century at Energy-Daily.com




Tempur-Pedic Mattress Comparison

Newsletters :: SpaceDaily Express :: SpaceWar Express :: TerraDaily Express :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News
New Oil Shale Technology Under Development
Washington (UPI) Jan 15, 2007
A U.S. Department of Energy project has demonstrated the viability of a new technology that might unlock the nation's largest potential source of oil.

.
Get Our Free Newsletters Via Email
  



  • Ex-OPEC Chief Says Crude Oil Market Oversupplied
  • New Oil Shale Technology Under Development
  • Earth Biofuels To Acquire Controlling Interest In Ethanol Production Facility
  • Brookhaven Lab Scientists Stabilize Platinum Electrocatalysts For Use In Fuel Cells

  • Most Germans Oppose Nuclear Power Phase-Out
  • Iran To 'Honor Principles' Of Nuclear Control Treaty
  • Australia And China Ratify Nuclear Fuel Deal
  • Poland Moves Closer To Joining Baltic Nuclear Plant Project

  • U.S. wood-fired boilers cause concern
  • Climate Change Affecting Outermost Atmosphere Of Earth
  • TIMED Celebrates 5-Year Anniversary
  • Steering Clear Of Icy Skies

  • Sweden's Tree Line Moving At Fastest Rate For 7,000 Years
  • Soil Nutrients Shape Tropical Forests, Large-Scale Study Indicates
  • Health Of Brazilian Rainforest Depends On Dust From One Valley In Africa
  • Forests Can Also Raise Temperature Of Earth

  • California's Big Freeze Threatening Citrus Crops
  • 150,000 Trout Killed At Fish Farm In Storm Off Norway
  • Clear Strong Guidelines Needed For Marine Aquaculture
  • Cloned Food Safe Despite Consumer Fears

  • When Will Russian Cars Go To Detroit
  • New Battery Era Fires Up GM
  • What Will Russians Drive In 2010
  • Chinese Carmakers Head West

  • USGS Examines Environmental Impacts Of Aircraft De-Icers
  • China Gives Rare Glimpse Of Homegrown Jet Fighter
  • IATA Gives Cautious Welcome To EU Emissions Trading Plan
  • EU Proposes CO2 Emission Quotas For Airlines

  • Could NASA Get To Pluto Faster? Space Expert Says Yes - By Thinking Nuclear
  • NASA plans to send new robot to Jupiter
  • Los Alamos Hopes To Lead New Era Of Nuclear Space Tranportion With Jovian Mission
  • Boeing Selects Leader for Nuclear Space Systems Program

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2006 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA PortalReports are copyright European Space Agency. All NASA sourced material is public domain. Additionalcopyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement