Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Taking the Heat: Pitt Team Conquers Hurdle to Nano Devices With First Metallic Nanoparticles Resistant to Extreme Heat

Abstract:
Just as a gecko sheds its tail, metal-alloy particles endure 850 degrees Celsius by ditching weaker components, researchers report in Nature Materials.

Taking the Heat: Pitt Team Conquers Hurdle to Nano Devices With First Metallic Nanoparticles Resistant to Extreme Heat

Pittsburgh, PA | Posted on December 2nd, 2009

A University of Pittsburgh team overcame a major hurdle plaguing the development of nanomaterials such as those that could lead to more efficient catalysts used to produce hydrogen and render car exhaust less toxic. The researchers reported Nov. 29 in Nature Materials the first demonstration of high-temperature stability in metallic nanoparticles, the vaunted next-generation materials hampered by a vulnerability to extreme heat.

Götz Veser, an associate professor and CNG Faculty Fellow of chemical and petroleum engineering in Pitt's Swanson School of Engineering, and Anmin Cao, the paper's lead author and a postdoctoral researcher in Veser's lab, created metal-alloy particles in the range of 4 nanometers that can withstand temperatures of more than 850 degrees Celsius, at least 250 degrees more than typical metallic nanoparticles. Forged from the catalytic metals platinum and rhodium, the highly reactive particles work by dumping their heat-susceptible components as temperatures rise, a quality Cao likened to a gecko shedding its tail in self-defense.

"The natural instability of particles at this scale is an obstacle for many applications, from sensors to fuel production," Veser said. "The amazing potential of nanoparticles to open up completely new fields and allow for dramatically more efficient processes has been shown in laboratory applications, but very little of it has translated to real life because of such issues as heat sensitivity. For us to reap the benefits of nanoparticles, they must withstand the harsh conditions of actual use."

Veser and Cao present an original approach to stabilizing metallic catalysts smaller than 5 nanometers. Materials within this size range boast a higher surface area and permit near-total particle utilization, allowing for more efficient reactions. But they also fuse together at around 600 degrees Celsius-lower than usual reaction temperatures for many catalytic processes-and become too large. Attempts to stabilize the metals have involved encasing them in heat-resistant nanostructures, but the most promising methods were only demonstrated in the 10- to 15-nanometer range, Cao wrote. Veser himself has designed oxide-based nanostructures that stabilized particles as small as 10 nanometers.

For the research in "Nature Materials," he and Cao blended platinum and rhodium, which has a high melting point. They tested the alloy via a methane combustion reaction and found that the composite was not only a highly reactive catalyst, but that the particles maintained an average size of 4.3 nanometers, even during extended exposure to 850-degree heat. In fact, small amounts of 4-nanometer particles remained after the temperature topped 950 degrees Celsius, although the majority had ballooned to eight-times that size.

Veser and Cao were surprised to find that the alloy did not simply endure the heat. It instead sacrificed the low-tolerance platinum then reconstituted itself as a rhodium-rich catalyst to finish the reaction. At around 700 degrees Celsius, the platinum-rhodium alloy began to melt. The platinum "bled" from the particle and formed larger particles with other errant platinum, leaving the more durable alloyed particles to weather on. Veser and Cao predicted that this self-stabilization would occur for all metal catalysts alloyed with a second, more durable metal.

Veser and Cao conducted their work with support from the National Energy Technology Laboratory, the lead research and development office for the U.S. Department of Energy's (DOE) Office of Fossil Energy, as well as the DOE's Office of Basic Energy Sciences and the National Science Foundation.

####

About University of Pittsburgh
Founded in 1787 as a small, private school, the Pittsburgh Academy was located in a log cabin near Pittsburgh’s three rivers. In the more than 220 years since, the University has evolved into an internationally recognized center of learning and research.

For more information, please click here

Contacts:
Morgan Kelly
412-624-4356 (office)
412-897-1400 (cell)

Copyright © University of Pittsburgh

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

News and information

Pixelligent Launches New PixClear® Light Extraction Materials for OLED Lighting August 4th, 2015

The annual meeting on High Power Diode Lasers & Systems will be held as part of the Enlighten Conference, October 14th & 15th August 4th, 2015

Atomic view of microtubules: Berkeley Lab researchers achieve record 3.5 angstroms resolution and visualize action of a major microtubule-regulating protein August 4th, 2015

World's quietest gas lets physicists hear faint quantum effects August 4th, 2015

Chemistry

March 2016; 6th Int'l Conference on Nanostructures in Iran July 29th, 2015

Meet the high-performance single-molecule diode: Major milestone in molecular electronics scored by Berkeley Lab and Columbia University team July 29th, 2015

'Seeing' molecular interactions could give boost to organic electronics July 28th, 2015

Quantum networks: Back and forth are not equal distances! July 28th, 2015

Possible Futures

Global Carbon Nanotubes Industry 2015: Acute Market Reports August 4th, 2015

Nanozirconia Market 2015 - Global Industry Survey, Analysis, Size, Share, Outlook and Forecast to 2020 July 31st, 2015

Self-Healing Nano Anti-rust Coatings Market 2015 - Global Industry Survey, Analysis, Size, Share, Outlook and Forecast to 2020 July 31st, 2015

Nano Spray Instrument Market 2015 - Global Industry Survey, Analysis, Size, Share, Outlook and Forecast to 2020 July 31st, 2015

Discoveries

Atomic view of microtubules: Berkeley Lab researchers achieve record 3.5 angstroms resolution and visualize action of a major microtubule-regulating protein August 4th, 2015

World's quietest gas lets physicists hear faint quantum effects August 4th, 2015

Artificial blood vessels become resistant to thrombosis August 4th, 2015

Engineering a better 'Do: Purdue researchers are learning how August 4th, 2015

Materials/Metamaterials

Engineering a better 'Do: Purdue researchers are learning how August 4th, 2015

Thin films offer promise for ferroelectric devices: Researchers at Tokyo Institute of Technology demystify the ferroelectric properties observed in hafnium-oxide-based thin films, revealing a potentially useful device material August 3rd, 2015

Self-assembling, biomimetic membranes may aid water filtration August 1st, 2015

Transparent, electrically conductive network of encapsulated silver nanowires: A novel electrode for optoelectronics August 1st, 2015

Announcements

Artificial blood vessels become resistant to thrombosis August 4th, 2015

Engineering a better 'Do: Purdue researchers are learning how August 4th, 2015

Proving nanoparticles in sunscreen products August 4th, 2015

Global Carbon Nanotubes Industry 2015: Acute Market Reports August 4th, 2015

Environment

March 2016; 6th Int'l Conference on Nanostructures in Iran July 29th, 2015

Laboratorial Performance of Nanocomposite Membrane Improved in Water Purification July 28th, 2015

Nanosorbents Reduce Amount of Heavy Metals in Petrochemical Wastewater July 23rd, 2015

Nanopaper as an optical sensing platform July 23rd, 2015

Automotive/Transportation

Sol-gel capacitor dielectric offers record-high energy storage July 30th, 2015

Controlling Dynamic Behavior of Carbon Nanosheets in Structures Made Possible July 30th, 2015

Ultra-thin hollow nanocages could reduce platinum use in fuel cell electrodes July 24th, 2015

Researchers boost wireless power transfer with magnetic field enhancement July 23rd, 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