Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

ORNL microscopy captures real-time view of evolving fuel cell catalysts

20.11.2015

Atomic-level imaging of catalysts by scientists at the Department of Energy's Oak Ridge National Laboratory could help manufacturers lower the cost and improve the performance of emission-free fuel cell technologies.

Fuel cells rely on costly platinum catalysts to enable the reactions that convert chemical energy into electricity. Alloying platinum with noble metals such as cobalt reduces the overall cost, but such alloyed catalysts vary in performance based on their atomic structure and processing history.


Models of platinum-cobalt nanoparticle catalysts illustrate how specific atomic configurations originate and evolve as the particles are heated.

Illustration by Andy Sproles, Oak Ridge National Laboratory, US Department of Energy.

An ORNL team used scanning transmission electron microscopy to track atomic reconfigurations in individual platinum-cobalt nanoparticle catalysts as the particles were heated inside the microscope. The in-situ measurements -- acquired in real time in the vacuum of the microscope column -- allowed the researchers to collect atomic level data that could not be obtained with conventional microscopy techniques. The results are published in Nature Communications.

"This is the first time individual nanoparticles have been tracked this way -- to image the structural and compositional changes at the atomic level from the start of an annealing process to the finish," ORNL coauthor Karren More said.

Very small changes in the positions of platinum and cobalt atoms affect the catalyst's overall activity and selectivity, so annealing -- a gradual heating, holding, and cooling process -- is often used to modify the alloy's surface structure. The ORNL in situ microscopy experiments documented exactly what, when and how specific atomic configurations originate and evolve during the annealing process.

"You can anneal something from room temperature to 800 degrees Celsius, but you don't know at which point you should stop the process to ensure the best catalytic performance," lead author Miaofang Chi said. "Because you don't know how the particle evolves, you might be missing the optimum surface configuration."

The atomic-level detail in the ORNL study will guide researchers and manufacturers who want to fine-tune their catalysts' atomic structure to meet the demands of a specific application.

"This work paves the way towards designing catalysts through post-synthesis annealing for optimized performance," Chi said.

###

The study is published as "Surface faceting and elemental diffusion behavior at atomic scale for alloy nanoparticles during in situ annealing." Coauthors are ORNL's Miaofang Chi, Karren More, Andrew Lupini and Lawrence Allard; Johns Hopkins University's Chao Wang; University of Pittsburgh's Yinkai Lei and Guofeng Wang; and Argonne National Laboratory's Dongguo Li, Nenad Markovic, and Vojislav Stamenkovic.

The research was sponsored by the Fuel Cell Technologies Office in DOE's Office of Energy Efficiency and Renewable Energy, and microscopy was performed at ORNL's Center for Nanophase Materials Sciences, a DOE Office of Science User Facility.

ORNL is managed by UT-Battelle for the Department of Energy's Office of Science. DOE's Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

Image: https://www.ornl.gov//sites/default/files/annealingIllust_1.jpeg

Caption: Models of platinum-cobalt nanoparticle catalysts illustrate how specific atomic configurations originate and evolve as the particles are heated. Illustration by Andy Sproles, Oak Ridge National Laboratory, U.S. Department of Energy.

NOTE TO EDITORS: You may read other press releases from Oak Ridge National Laboratory or learn more about the lab at http://www.ornl.gov/news. Additional information about ORNL is available at the sites below:
Twitter - http://twitter.com/ornl
RSS Feeds - http://www.ornl.gov/ornlhome/rss_feeds.shtml
Flickr - http://www.flickr.com/photos/oakridgelab
YouTube - http://www.youtube.com/user/OakRidgeNationalLab
LinkedIn - http://www.linkedin.com/companies/oak-ridge-national-laboratory
Facebook - http://www.facebook.com/Oak.Ridge.National.Laboratory

Media Contact

Morgan McCorkle
mccorkleml@ornl.gov
865-574-7308

 @ORNL

http://www.ornl.gov 

Morgan McCorkle | EurekAlert!

More articles from Power and Electrical Engineering:

nachricht A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes
20.07.2018 | Science China Press

nachricht Future electronic components to be printed like newspapers
20.07.2018 | Purdue University

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>