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 Laser sensor LAH-G1 - optical distance sensors with measurement value display
15.08.2017 | WayCon Positionsmesstechnik GmbH

nachricht Engineers find better way to detect nanoparticles
14.08.2017 | Washington University in St. Louis

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>