Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Uniform Tungsten Trimers Stand and Deliver

19.09.2006
Research provides fundamental insights into catalyst structure and behavior

Like tiny nano-soldiers on parade, the cyclic tungsten trioxide clusters line up molecule-by-molecule on the titanium dioxide platform. One tungsten atom from each cluster is raised slightly, holding forth the potential to execute catalytic reactions.

The nanostructures constitute a new model system, a simplified version of a catalyst that would be used in an application. Such models reveal to chemists the exact structure and reaction mechanisms of metal oxides.

Developed by researchers from the Department of Energy’s Pacific Northwest National Laboratory, the University of Texas-Austin and Washington State University, the discovery may offer a platform for fundamental reactivity studies of metal oxides used as catalysts in converting hydrocarbons into fuels and value-added chemicals.

... more about:
»Atom »Oxide »catalyst »tungsten

“There is a striking difference between commercial catalysts and the new model system,” said Mike White, the UT professor leading the PNNL Institute for Interfacial Catalysis. Variability in commercial catalyst size and chemical composition makes it difficult to accurately understand or describe the reactions taking place at a molecular level.

“Commercial catalysts are like a gravel pile with many sizes of rocks. Some rocks are purple; some are blue. Some do one thing; some do another. But, our system has all the same size rocks,” White said.

The model system – in which all the molecular clusters are the same size, are evenly dispersed and are oriented in one of two directions on a single layer of titanium oxide crystals – holds promise as a platform for studying the behavior of early transition metal oxides. White noted, “While we have created the smallest nano-cluster of a uniform size you can imagine, it is a real oxide. The tungsten is in its normal oxide state. In principle, you have all the things needed to make bonds and break bonds. That’s the scientific breakthrough here.”

Though it appears simple, the model system was challenging to develop, White said. The collaborators employed specialized equipment available from the William R. Wiley Environmental Molecular Sciences Laboratory, a DOE user facility located at PNNL, to prepare and characterize the platform as well as the clusters. Using a unique approach that changed the tungsten oxide directly from a solid to a gas, the collaborators stabilized the molecular rings – or “trimers” – of tungsten on the titanium platform.

A scanning tunneling microscope imaged not only the trimers but also their consistent alignment with the single crystal structure of the platform. “A scanning tunneling microscope must be so stable that we have to vibrationally isolate the instrument. It cannot move even a small amount because we are using a stream of electrons to measure the distance from the microscope’s tip to a small space between atoms,” White explained. The collaborators also characterized the cluster mass, determined the ratio of tungsten to oxygen atoms in the cluster, and used X-ray photoelectron spectroscopy to identify the tungsten oxidation state.

“This is a small piece of the basic science that could lead to control of chemical transformations for our energy future,” White said, noting that this is the first time researchers have created and imaged monodisperse oxide clusters on another oxide.

Work to develop the model system is part of the Early Transition Metals as Catalysts project at PNNL and was supported by the U.S. Department of Energy’s Office of Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division. Results were published in the July 17, 2006 issue of Angewandte Chemie International Edition.

Judith Graybeal | EurekAlert!
Further information:
http://www.pnl.gov

Further reports about: Atom Oxide catalyst tungsten

More articles from Life Sciences:

nachricht Designer cells: artificial enzyme can activate a gene switch
22.05.2018 | Universität Basel

nachricht Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Designer cells: artificial enzyme can activate a gene switch

22.05.2018 | Life Sciences

PR of MCC: Carbon removal from atmosphere unavoidable for 1.5 degree target

22.05.2018 | Earth Sciences

Achema 2018: New camera system monitors distillation and helps save energy

22.05.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>