Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Evolution of a Bimetallic Nanocatalyst

TEM image of platinum/cobalt bimetallic nanoparticle catalyst in action shows that during the oxidation reaction, cobalt atoms migrate to the surface of the particle, forming a cobalt oxide epitaxial film, like water on oil.
TEM image of platinum/cobalt bimetallic nanoparticle catalyst in action shows that during the oxidation reaction, cobalt atoms migrate to the surface of the particle, forming a cobalt oxide epitaxial film, like water on oil.

Abstract:
Atomic-scale snapshots of a bimetallic nanoparticle catalyst in action have provided insights that could help improve the industrial process by which fuels and chemicals are synthesized from natural gas, coal or plant biomass. A multi-national lab collaboration led by researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) has taken the most detailed look ever at the evolution of platinum/cobalt bimetallic nanoparticles during reactions in oxygen and hydrogen gases.

Evolution of a Bimetallic Nanocatalyst

Berkeley, CA | Posted on June 6th, 2014

"Using in situ aberration-corrected transmission electron microscopy (TEM), we found that during the oxidation reaction, cobalt atoms migrate to the nanoparticle surface, forming a cobalt oxide epitaxial film, like water on oil," says Haimei Zheng, a staff scientist in Berkeley Lab's Materials Sciences Division who led this study. "During the hydrogen reduction reaction, cobalt atoms migrate back into the bulk, leaving a monolayer of platinum on the surface. This atomic information provides an important reference point for designing and engineering better bimetallic catalysts in the future."

Zheng, a 2011 recipient of a DOE Office of Science Early Career Award, is the corresponding author of a paper describing this research in the journal NANO Letters entitled "Revealing the Atomic Restructuring of Pt-Co Nanoparticles." Co-authors at Berkeley are Huolin Xin, Selim Alayoglu, Runzhe Tao, Lin-Wang Wang, Miquel Salmeron and Gabor Somorjai. Other co-authors are Chong-Min Wang and Libor Kovarik, of the Pacific Northwest National Laboratory (PNNL), Eric Stach of Brookhaven National Laboratory (BNL), and Arda Genc of the FEI Company in Oregon.

Bimetallic catalysts are drawing considerable attention from the chemical industry these days because in many cases they offer superior performances to their monometallic counterparts. There is also the possibility of tuning their catalytic performances to meet specific needs. A bimetallic catalyst of particular interest entails the pairing of platinum, the gold standard of monometallic catalysts, with cobalt, a lesser catalyst but one that is dramatically cheaper than platinum. The platinum/cobalt catalyst is not only considered a model system for the study of other bimetallic nanocatalysts, it is also an excellent promoter of the widely used Fischer-Tropsch process, in which mixtures of hydrogen and carbon monoxide are converted into long-chain carbons for use as fuels or in low-temperature fuel cells.

"While there have been many studies on platinum/cobalt and other bimetallic catalysts, information on how reactions proceed atomically and what the morphology looks like has been missing," Zheng says. "To acquire this information it was necessary to map the atomic structures in reactive environments in situ, which we did using specially equipped TEMs."

The in situ environmental TEM experiments were carried out at both the Environmental Molecular Sciences Laboratory, which is located at PNNL, and at BNL's Center for Functional Nanomaterials. Ex situ aberration-corrected TEM imaging was done at Berkeley Lab's National Center for Electron Microscopy using TEAM 0.5, the world's most powerful TEM.

"This work is an excellent example of collaborative team-work among multiple institutes," Zheng says. "Having access to such high-end resources and being able to form such close team collaborations strengthens our ability to tackle challenging scientific problems."

The in situ aberration corrected TEM studies of Zheng and her colleagues revealed that because of a size mismatch between the lattices of the cobalt oxide epitaxial film and the platinum surface, the cobalt oxide lattice is compressively strained at the interface to fit on the platinum lattice. As the strain energy relaxes, the cobalt oxide film starts breaking up to form distinct molecular islands on the platinum surface. This reduces the effective reaction surface area per volume and creates catalytic voids, both of which impact overall catalytic performance.

"By taking this segregation of the platinum and cobalt atoms into consideration, the interfacial strain that arises during oxidation can be predicted," Zheng says. "We can then design nanoparticle catalysts to ensure that during reactions the material with higher catalytic performance will be on surface of the nanoparticles."

Zheng adds that the ability to observe atomic scale details of the evolution of the structure of nanoparticles in their reactive environments not only opens the way to a deeper understanding of bimetallic nanoparticle catalysis, it also allows for the study of a wider variety of nanoparticle systems where reaction pathways remain elusive.

This research was supported by the DOE Office of Science. It made use of the resources at the Environmental Molecular Sciences Laboratory, the Center for Functional Nanomaterials, and the National Center for Electron Microscope, user facilities supported by DOE's Office of Science.

####

About DOE/Lawrence Berkeley National Laboratory
Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.

The U.S. Department of Energy’s Office of Science, the single largest supporter of basic research in the physical sciences in the United States, is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

For more information, please click here

Contacts:
Lynn Yarris

510-486-5375

Copyright © DOE/Lawrence Berkeley National Laboratory

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 Links

For more information about the research of Haimei Zheng go here:

For more information on Berkeley Lab’s National Center for Electron Microscopy go here:

For more information about the Environmental Molecular Sciences Laboratory go here:

For more information about BNL’s Center for Functional Nanoparticles go here:

Related News Press

News and information

SEFCU, SUNY Poly CNSE Announce Winning Student-Led Teams in the 6th Annual $500,000 New York Business Plan Competition April 25th, 2015

Northwestern scientists develop first liquid nanolaser: Technology could lead to new way of doing 'lab on a chip' medical diagnostics April 25th, 2015

Nanotech-enabled moisturizer speeds healing of diabetic skin wounds: Spherical nucleic acids silence gene that interferes with wound healing April 24th, 2015

Fast and accurate 3-D imaging technique to track optically trapped particles April 24th, 2015

Pseudoparticles travel through photoactive material: KIT scientists measure important process in the conversion of light energy -- publication in Nature Communications April 24th, 2015

Imaging

Fast and accurate 3-D imaging technique to track optically trapped particles April 24th, 2015

ORNL reports method that takes quantum sensing to new level April 23rd, 2015

A silver lining: UCSB researchers cradle silver nanoclusters inside synthetic DNA to create a programmed, tunable fluorescent array April 23rd, 2015

Richards-Kortum elected to American Academy of Arts and Sciences: April 22nd, 2015

Laboratories

ORNL reports method that takes quantum sensing to new level April 23rd, 2015

Scientists Use Nanoscale Building Blocks and DNA 'Glue' to Shape 3D Superlattices: New approach to designing ordered composite materials for possible energy applications April 23rd, 2015

Drexel materials scientists putting a new spin on computing memory April 22nd, 2015

Chemistry

Scientists Use Nanoscale Building Blocks and DNA 'Glue' to Shape 3D Superlattices: New approach to designing ordered composite materials for possible energy applications April 23rd, 2015

Govt.-Legislation/Regulation/Funding/Policy

SEFCU, SUNY Poly CNSE Announce Winning Student-Led Teams in the 6th Annual $500,000 New York Business Plan Competition April 25th, 2015

Northwestern scientists develop first liquid nanolaser: Technology could lead to new way of doing 'lab on a chip' medical diagnostics April 25th, 2015

ORNL reports method that takes quantum sensing to new level April 23rd, 2015

Electron spin brings order to high entropy alloys April 23rd, 2015

Discoveries

SEFCU, SUNY Poly CNSE Announce Winning Student-Led Teams in the 6th Annual $500,000 New York Business Plan Competition April 25th, 2015

Northwestern scientists develop first liquid nanolaser: Technology could lead to new way of doing 'lab on a chip' medical diagnostics April 25th, 2015

Nanotech-enabled moisturizer speeds healing of diabetic skin wounds: Spherical nucleic acids silence gene that interferes with wound healing April 24th, 2015

Fast and accurate 3-D imaging technique to track optically trapped particles April 24th, 2015

Materials/Metamaterials

Electron spin brings order to high entropy alloys April 23rd, 2015

Scientists Use Nanoscale Building Blocks and DNA 'Glue' to Shape 3D Superlattices: New approach to designing ordered composite materials for possible energy applications April 23rd, 2015

Surface matters: Huge reduction of heat conduction observed in flat silicon channels April 23rd, 2015

Nanoparticles Used to Improve Mechanical, Thermal Properties of Cellulose Fibers April 23rd, 2015

Announcements

SEFCU, SUNY Poly CNSE Announce Winning Student-Led Teams in the 6th Annual $500,000 New York Business Plan Competition April 25th, 2015

Northwestern scientists develop first liquid nanolaser: Technology could lead to new way of doing 'lab on a chip' medical diagnostics April 25th, 2015

Nanotech-enabled moisturizer speeds healing of diabetic skin wounds: Spherical nucleic acids silence gene that interferes with wound healing April 24th, 2015

Fast and accurate 3-D imaging technique to track optically trapped particles April 24th, 2015

Energy

Pseudoparticles travel through photoactive material: KIT scientists measure important process in the conversion of light energy -- publication in Nature Communications April 24th, 2015

Scientists Use Nanoscale Building Blocks and DNA 'Glue' to Shape 3D Superlattices: New approach to designing ordered composite materials for possible energy applications April 23rd, 2015

'Holey' graphene for energy storage: Charged holes in graphene increase energy storage capacity April 22nd, 2015

Expanding the reach of metallic glass April 22nd, 2015

Fuel Cells

Expanding the reach of metallic glass April 22nd, 2015

Newly-Developed Nanocatalysts Increase Performance of Fuel Cells April 16th, 2015

Cobalt film a clean-fuel find: Rice University discovery is efficient, robust at drawing hydrogen and oxygen from water April 15th, 2015

Research could usher in next generation of batteries, fuel cells University of South Carolina and Clemson reseachers uncover clean interfaces April 10th, 2015

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