Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Modeling the chemical reactions of nanoparticles


As science enters the world of the very small, researchers will be searching for new ways to study nanoparticles and their properties. For the past several years, scientists at the U.S. Department of Energy’s Brookhaven National Laboratory have been experimenting with new methods for preparing nanoparticles on metal supports, with the aim of creating model catalyst systems to better study the special reactivity of nano-sized catalyst particles.

Brookhaven’s Jan Hrbek will review several of the Lab’s results at the 231st national meeting of the American Chemical Society at the Georgia World Congress Center in Atlanta, GA. Hrbek’s talk will be held on Monday, March 27 at 2:40 pm in Room C209.

Catalysis, the acceleration of a chemical reaction, is tremendously important as an industrial process, underlying most of our energy supply (oil-to-fuel conversion, for example) and 80 percent of the products of the chemical industry. There is a substantial need to understand how catalysts work, and learn to design and make better catalysts. The work at Brookhaven is aimed at understanding how the detailed atomic structures of model systems of certain classes of catalysts contribute to their activity. Hrbek’s talk will review work in making models of nanometer scale particles that are the active material in many catalyst particles.

Solid surfaces often act as catalysts by binding molecules, weakening their internal bonds and allowing them to react to form new molecular products. These solid surfaces are usually nanometer-sized particles supported on micron-sized powder particles. Reacting gases or liquids flow over them to undergo reactions into the desired products. Examples of active materials include metals, metal oxides, and other metal compounds (metal sulfides and metal carbides, for example). These are known collectively as heterogeneous catalysts since they are in a separate (solid) phase from the reacting gas or liquid stream that flows over them. Very tiny particles allow most of the solid material’s atoms to be at the surface, in contact with the reacting stream. This fine dispersion is necessary to guarantee efficient use of the catalyst material. The nanometer size also is often important in improving the reactivity and selectivity of the particles. These tiny particles are often strained and the strain can promote formation of more stable active sites for a particular chemical transformation.

"Actual catalysts are very complex, not well controlled materials, often with a wide range of particle sizes and structures," Hrbek said. "It is often difficult to sort out which atomic sites are catalytically active. The goals of these model studies are to be able to determine atomic structures of the reactive sites, and to understand how reactions occur at those sites. This work ultimately aims to strengthen our ability to design better catalysts."

Among the most interesting results of the Brookhaven studies is a new method to create well-defined nanoparticles of metal compounds that are of catalytic interest.

"Reactive layer assisted deposition, or RLAD, allows us to make well-dispersed, reasonably uniform nanoparticles of metal compounds on well-defined supports," Hrbek said. "These can then be structurally characterized on the nano scale and their reactivity evaluated by using modern surface-sensitive techniques. This opens an interesting opportunity to examine catalytic activity in metal compounds that were also atomically characterized."

Several other laboratories studying nanoparticles of metal compounds have already adopted the RLAD method.

"It is a challenge to form uniform particles in this size range, to disperse them uniformly on the substrate, and to ’look’ at them with advanced microscopies to understand their structure," Hrbek said. "The tools being applied to form and study the particles are one aspect of Brookhaven’s growing capabilities in nanoscience."

Kay Cordtz | EurekAlert!
Further information:

More articles from Materials Sciences:

nachricht Scientists have a new way to gauge the growth of nanowires
19.03.2018 | DOE/Argonne National Laboratory

nachricht Researchers demonstrate existence of new form of electronic matter
15.03.2018 | University of Illinois at Urbana-Champaign

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Physicists made crystal lattice from polaritons

20.03.2018 | Physics and Astronomy

Mars' oceans formed early, possibly aided by massive volcanic eruptions

20.03.2018 | Physics and Astronomy

Thawing permafrost produces more methane than expected

20.03.2018 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>