Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > New cobalt-graphene catalyst could challenge platinum for use in fuel cells: Performs nearly as well as precious metal catalysts

Nanoparticles of cobalt attach themselves to a graphene substrate in a single layer. As a catalyst, the cobalt-graphene combination was a little slower getting the oxygen reduction reaction going, but it reduced oxygen faster and lasted longer than platinum-based catalysts.

Credit: Sun Lab/Brown University
Nanoparticles of cobalt attach themselves to a graphene substrate in a single layer. As a catalyst, the cobalt-graphene combination was a little slower getting the oxygen reduction reaction going, but it reduced oxygen faster and lasted longer than platinum-based catalysts.

Credit: Sun Lab/Brown University

Abstract:
There's a new contender in the race to find an inexpensive alternative to platinum catalysts for use in hydrogen fuel cells.

New cobalt-graphene catalyst could challenge platinum for use in fuel cells: Performs nearly as well as precious metal catalysts

Providence, RI | Posted on October 17th, 2012

Brown University chemist Shouheng Sun and his students have developed a new material a graphene sheet covered by cobalt and cobalt-oxide nanoparticles that can catalyze the oxygen reduction reaction nearly as well as platinum does and is substantially more durable.

The new material "has the best reduction performance of any nonplatinum catalyst," said Shaojun Guo, postdoctoral researcher in Sun's lab and lead author of a paper published online in the journal Angewandte Chemie International Edition.

The oxygen reduction reaction occurs on the cathode side of a hydrogen fuel cell. Oxygen functions as an electron sink, stripping electrons from hydrogen fuel at the anode and creating the electrical pull that keeps the current running through electrical devices powered by the cell. "The reaction requires a catalyst, and platinum is currently the best one," said Sun. "But it's very expensive and has a very limited supply, and that's why you don't see a lot of fuel cell use aside from a few special purposes."

Thus far scientists have been unable to develop a viable alternative. A few researchers, including Sun and Guo, have developed new catalysts that reduce the amount of platinum required, but an effective catalyst that uses no platinum at all remains elusive.

This new graphene-cobalt material is the most promising candidate yet, the researchers say. It is the first catalyst not made from a precious metal that comes close to matching platinum's properties.

Lab tests performed by Sun and his team showed that the new graphene-cobalt material was a bit slower than platinum in getting the oxygen reduction reaction started, but once the reaction was going, the new material actually reduced oxygen at a faster pace than platinum. The new catalyst also proved to be more stable, degrading much more slowly than platinum over time. After about 17 hours of testing, the graphene-cobalt catalyst was performing at around 70 percent of its initial capacity. The platinum catalyst the team tested performed at less than 60 percent after the same amount of time.

Cobalt is an abundant metal, readily available at a fraction of what platinum costs. Graphene is a one-atom-thick sheet of carbon atoms arranged in a honeycomb structure. Developed in the last few years, graphene is renowned for its strength, electrical properties, and catalytic potential.

Self-assembly process

Often, graphene nanoparticle materials are made by growing nanoparticles directly on the graphene surface. But that process is problematic for making a catalyst, Sun said. "It's really difficult to control the size, shape, and composition of nanoparticles," he said.

Sun and his team used a self-assembly method that gave them more control over the material's properties. First, they dispersed cobalt nanoparticles and graphene in separate solutions. The two solutions were then combined and pounded with sound waves to make sure they mixed thoroughly. That caused the nanoparticles to attach evenly to the graphene in a single layer, which maximizes the potential of each particle to be involved in the reaction. The material was then pulled out of solution using a centrifuge and dried. When exposed to air, outside layers of atomic cobalt on each nanoparticle are oxidized, forming a shell of cobalt-oxide that helps protect the cobalt core.

The researchers could control the thickness of the cobalt-oxide shell by heating the material at 70 degrees Celsius for varying amounts of time. Heating it longer increased the thickness of the shell. This way, they could fine-tune the structure in search of a combination that gives top performance. In this case, they found that a 1-nanometer shell of cobalt-oxide optimized catalytic properties.

Sun and his team are optimistic that with more study their material could one day be a suitable replacement for platinum catalysts. "Right now, it's comparable to platinum in an alkaline medium," Sun said, "but it's not ready for use yet. We still need to do more tests."

Ultimately, Sun says, finding a suitable nonplatinum catalyst is the key to getting fuel cells out of the laboratory phase and into production as power sources for cars and other devices.

####

For more information, please click here

Contacts:
Kevin Stacey

401-863-3766

Copyright © Brown University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Graphene/ Graphite

Graphene leans on glass to advance electronics: Scientists' use of common glass to optimize graphene's electronic properties could improve technologies from flat screens to solar cells February 12th, 2016

A metal that behaves like water: Researchers describe new behaviors of graphene February 12th, 2016

Graphene decharging and molecular shielding February 8th, 2016

From allergens to anodes: Pollen derived battery electrodes February 8th, 2016

News and information

'Lasers rewired': Scientists find a new way to make nanowire lasers: Berkeley Lab, UC Berkeley scientists adapt next-gen solar cell materials for a different purpose February 12th, 2016

Breaking cell barriers with retractable protein nanoneedles: Adapting a bacterial structure, Wyss Institute researchers develop protein actuators that can mechanically puncture cells February 12th, 2016

Replacement of Toxic Antibacterial Agents Possible by Biocompatible Polymeric Nanocomposites February 12th, 2016

Properties of Polymeric Nanofibers Optimized to Treat Damaged Body Tissues February 12th, 2016

Chemistry

Chemical cages: New technique advances synthetic biology February 10th, 2016

Graphene decharging and molecular shielding February 8th, 2016

Self Assembly

New type of nanowires, built with natural gas heating: UNIST research team developed a new simple nanowire manufacturing technique February 1st, 2016

Researchers develop completely new kind of polymer: Hybrid polymers could lead to new concepts in self-repairing materials, drug delivery and artificial muscles January 30th, 2016

Polymer nanowires that assemble in perpendicular layers could offer route to tinier chip components January 23rd, 2016

Nanodevice, build thyself: Researchers in Germany studied how a multitude of electronic interactions govern the encounter between a molecule called porphine and copper and silver surfaces January 18th, 2016

Discoveries

'Lasers rewired': Scientists find a new way to make nanowire lasers: Berkeley Lab, UC Berkeley scientists adapt next-gen solar cell materials for a different purpose February 12th, 2016

Breaking cell barriers with retractable protein nanoneedles: Adapting a bacterial structure, Wyss Institute researchers develop protein actuators that can mechanically puncture cells February 12th, 2016

Replacement of Toxic Antibacterial Agents Possible by Biocompatible Polymeric Nanocomposites February 12th, 2016

Properties of Polymeric Nanofibers Optimized to Treat Damaged Body Tissues February 12th, 2016

Announcements

Graphene leans on glass to advance electronics: Scientists' use of common glass to optimize graphene's electronic properties could improve technologies from flat screens to solar cells February 12th, 2016

Breaking cell barriers with retractable protein nanoneedles: Adapting a bacterial structure, Wyss Institute researchers develop protein actuators that can mechanically puncture cells February 12th, 2016

Replacement of Toxic Antibacterial Agents Possible by Biocompatible Polymeric Nanocomposites February 12th, 2016

Properties of Polymeric Nanofibers Optimized to Treat Damaged Body Tissues February 12th, 2016

Automotive/Transportation

Electric-car battery materials could harm key soil bacteria February 11th, 2016

Canadian physicists discover new properties of superconductivity February 8th, 2016

Researchers develop completely new kind of polymer: Hybrid polymers could lead to new concepts in self-repairing materials, drug delivery and artificial muscles January 30th, 2016

An alternative to platinum: Iron-nitrogen compounds as catalysts in graphene January 28th, 2016

Fuel Cells

An alternative to platinum: Iron-nitrogen compounds as catalysts in graphene January 28th, 2016

Teijin to Participate in Nano Tech 2016 January 21st, 2016

Fuel cell advance: Research team reports success with low-cost nickel-based catalyst January 18th, 2016

Production of Graphene Oxide Nanosheets to Economize Fuel Cells January 1st, 2016

NanoNews-Digest
The latest news from around the world, FREE





  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic