Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cleaner Fuel by Nanoparticles

06.02.2007
Bulk molybdenum disulphide (MoS2) is a ubiquitous, standard solid lubricant. However, extremely small MoS2 nanoparticles have a potentially important application as a catalyst for producing sulphur-free fuels.

It is well known that material properties change when reducing particle sizes. However, for MoS2 nanoparticles the size-dependent deviations from the bulk properties are more pronounced than in other materials. Researchers at the Technical University Dresden and the Forschungszentrum Dresden-Rossendorf have studied in detail the influence of the particle size on the physical and chemical properties of MoS2.



Multi-walled MoS2 nano-octahedron; courtesy by A. Enyashin, TU Dresden.

It was shown for the first time that not only the size, but also the shape of the particle matters for the catalytic potential in fuel desulphurisation. The results have been recently reported in Angewandte Chemie (46/2007) and Nature Nanotechnology (2/2007).

Very small, sulphur-rich MoS2 nanoplatelets are well known as active catalysts for the desulphurisation of fuels. It has recently been shown that the catalytic potential increases dramatically with decreasing particle size. This effect has been correlated with the specific structure along the edges of triangular nanoplatelets. In contrast to the semi-conducting bulk the edges of the MoS2 nanoplatelets are electronically conducting and this is where sulphur-containing impurities in the fuel are decomposed.

An international team of researchers from the Technical University Dresden, the Forschungszentrum Dresden-Rossendorf, both in Germany, and at the Weizmann Institute in Rehovot, Israel, have examined the properties of larger particles with many long and well accessible edges. It was found that larger, regular three-dimensional particles promise a desulphurisation potential that is similar to the nanoplatelets. Such particles have an octahedral form that is similar to a bipyramid and require less effort in their production than the nanoplatelets that are ideally synthesised directly on a gold support and cover it like a nanoconfetti.

For the first time, the research team has shown that the potential for the desulphurisation of fuels is not limited to the smallest MoS2 particles, as the electronically conducting catalytic reaction sites also occur in larger particles. Thus, the particle size and the three-dimensional structure crucially determine the physical and chemical properties of MoS2 nanoparticles.

A joint theoretical and experimental investigation correlated the particle size and shape to the structural and electronic properties that are responsible for the catalytic activity of MoS2 nanoparticles. Platelets, fullerenes or even nanotubes, MoS2 nanoparticles larger than 10 nanometres are semi-conducting like the bulk. In contrast, within a diameter range of 3 to 7 nanometres regular, three-dimensional structures occur that are composed of eight equilateral triangles. Such particles have successfully been synthesised and observed experimentally by transmission electron microscopy. For the edges and corners of such nano-octahedra the quantum-mechanical calculations of the researchers from Dresden predict similar metallic properties to those found in the catalytically active nanoplatelets. According to the model calculations, single-walled nano-octahedra with a few hundred atoms are not stable. However, the observed multi-walled particles of nested octahedra are predicted to be more stable species which promise similar catalytic potential as the smaller nanoplatelets (Angew. Chem., Int. Ed. 46 (2007), 623).

Christine Bohnet | alfa
Further information:
http://www.fzd.de

More articles from Ecology, The Environment and Conservation:

nachricht Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel

nachricht Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: Computer-Designed Customized Regenerative Heart Valves

Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.

Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...

Im Focus: Light-induced superconductivity under high pressure

A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.

Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...

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

Supersonic waves may help electronics beat the heat

18.05.2018 | Power and Electrical Engineering

Keeping a Close Eye on Ice Loss

18.05.2018 | Information Technology

CrowdWater: An App for Flood Research

18.05.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>