Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Atomic insight may lead to cleaner cars

26.09.2003


MIT researchers affiliated with the Laboratory for Energy and the Environment are gaining atomic-level insight into how sulfur in engine exhaust “poisons” advanced catalytic converters, reducing their ability to remove noxious emissions from car engines. Understanding that process is a first step toward preventing it, thereby making viable new fuel-efficient engine designs.


Based on quantum mechanical calculations, MIT researchers have developed this series of pictures showing how sulfur dioxide on a platinum catalyst converts to sulfur trioxide—a compound that poisons advanced catalytic converters for new fuel-efficient engines. Platinum atoms of the catalyst’s surface appear as blue spheres, oxygen atoms are black and the sulfur atom is white. In successive pictures, a single oxygen atom approaches and eventually joins onto an existing sulfur dioxide molecule to form sulfur trioxide.
IMAGE / LABORATORY FOR ENERGY AND THE ENVIRONMENT



“Removing sulfur from fuel is difficult and costly, so we need to develop a sulfur-resistant catalytic converter that will work with the lean-running engines now being designed,” said Bernhardt Trout, associate professor of chemical engineering and principal investigator of the work. “Lean-running engines operate with excess air and are highly efficient, which means low fuel consumption and low emissions.”

... mehr zu:
»Alliance »Atomic »Science »Trout


The work focuses on a promising catalytic converter with two components: a platinum catalyst that converts carbon monoxide and hydrocarbons in exhaust to carbon dioxide and water, and a barium oxide “trap” that captures nitrogen oxides. The converter thus controls emissions that can harm human health and contribute to the formation of smog and acid rain.

However, with excess oxygen present, sulfur dioxide in the exhaust reacts on the platinum catalyst to form sulfur trioxide. The sulfur trioxide then coats the barium oxide trap, so it can no longer do its job.

“Our goal is to stop the reactions that turn sulfur dioxide to sulfur trioxide but without interfering with the reactions that clean up carbon monoxide and hydrocarbons,” said Trout. “That’s challenging because all of those reactions involve the same process—adding an oxygen atom to an existing molecule.”

Achieving “selective oxidation” is next to impossible using traditional trial-and-error experimentation. So the MIT researchers are using quantum mechanical calculations to determine on an atomic level the reaction process by which sulfur trioxide forms. Calculating the behavior of all electrons during the reactions of interest is a computationally intensive procedure that they perform on supercomputers at the National Computational Science Alliance at the University of Illinois at Urbana-Champaign.

Based on their analysis, Professor Trout and his team have developed a series of pictures that show the step-by-step process whereby a single oxygen atom on a platinum surface approaches and eventually joins onto an existing sulfur dioxide molecule to form sulfur trioxide. Other calculations show the energy consumed or released at each step as chemical bonds break or form.

The researchers are now using their new atomic-level understanding to perform larger-scale simulations that can predict how sulfur and oxygen atoms will move, interact and react to form new molecules under realistic conditions. Simulations thus far suggest that oxygen atoms will cluster together—a behavior observed in experimental systems.

Professor Trout and his team are collaborating closely with experimentalists to try to understand the clustering process and whether steps to either encourage or discourage clustering may interfere with the formation of sulfur trioxide.

This research is supported by the Ford/MIT Alliance and the National Science Foundation. Other participants are William Schneider of Ford Motor Co.; Xi Lin (Ph.D. 2003), a postdoctoral associate in the Department of Nuclear Engineering; and Hairong Tang, a Ph.D. candidate in the Department of Chemical Engineering.

Nancy Stauffer | MIT

Weitere Berichte zu: Alliance Atomic Science Trout

Weitere Nachrichten aus der Kategorie Verfahrenstechnologie:

nachricht Kleben ohne Klebstoff - Schnelles stoffschlüssiges Fügen von Metall und Thermoplast
22.02.2018 | Fraunhofer-Institut für Werkstoff- und Strahltechnik IWS

nachricht Wackelpudding mit Gedächtnis – Verlaufsvorhersage für handelsübliche Lacke
15.12.2017 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA

Alle Nachrichten aus der Kategorie: Verfahrenstechnologie >>>

Die aktuellsten Pressemeldungen zum Suchbegriff Innovation >>>

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

Im Focus: Vorstoß ins Innere der Atome

Mit Hilfe einer neuen Lasertechnologie haben es Physiker vom Labor für Attosekundenphysik der LMU und des MPQ geschafft, Attosekunden-Lichtblitze mit hoher Intensität und Photonenenergie zu produzieren. Damit konnten sie erstmals die Interaktion mehrere Photonen in einem Attosekundenpuls mit Elektronen aus einer inneren atomaren Schale beobachten konnten.

Wer die ultraschnelle Bewegung von Elektronen in inneren atomaren Schalen beobachten möchte, der benötigt ultrakurze und intensive Lichtblitze bei genügend...

Im Focus: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

Eine Gruppe von Forschern um Andrea Cavalleri am Max-Planck-Institut für Struktur und Dynamik der Materie (MPSD) in Hamburg hat eine Methode demonstriert, die es erlaubt die interatomaren Kräfte eines Festkörpers detailliert auszumessen. Ihr Artikel Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, nun online in Nature veröffentlich, erläutert, wie Terahertz-Laserpulse die Atome eines Festkörpers zu extrem hohen Auslenkungen treiben können.

Die zeitaufgelöste Messung der sehr unkonventionellen atomaren Bewegungen, die einer Anregung mit extrem starken Lichtpulsen folgen, ermöglichte es der...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Verlässliche Quantencomputer entwickeln

Internationalem Forschungsteam gelingt wichtiger Schritt auf dem Weg zur Lösung von Zertifizierungsproblemen

Quantencomputer sollen künftig algorithmische Probleme lösen, die selbst die größten klassischen Superrechner überfordern. Doch wie lässt sich prüfen, dass der...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

VideoLinks
Industrie & Wirtschaft
Veranstaltungen

Von festen Körpern und Philosophen

23.02.2018 | Veranstaltungen

Spannungsfeld Elektromobilität

23.02.2018 | Veranstaltungen

DFG unterstützt Kongresse und Tagungen - April 2018

21.02.2018 | Veranstaltungen

VideoLinks
Wissenschaft & Forschung
Weitere VideoLinks im Überblick >>>
 
Aktuelle Beiträge

Vorstoß ins Innere der Atome

23.02.2018 | Physik Astronomie

Wirt oder Gast? Proteomik gibt neue Aufschlüsse über Reaktion von Rifforganismen auf Umweltstress

23.02.2018 | Biowissenschaften Chemie

Wie Zellen unterschiedlich auf Stress reagieren

23.02.2018 | Biowissenschaften Chemie

Weitere B2B-VideoLinks
IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics