Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Dynamic catalytic converters for clean air in the city

27.10.2017

Dynamic structure of platinum particles optimizes exhaust gas aftertreatment, German-French cooperation, publication in the journal 'Angewandte Chemie'

Reducing pollutant emission of vehicles and meeting stricter exhaust gas standards are major challenges when developing catalytic converters. A new concept might help to efficiently treat exhaust gases after the cold start of engines and in urban traffic and to reduce the consumption of expensive noble metal.


The catalytic converter of a car converts toxic carbon monoxide (CO) into non-toxic carbon dioxide (CO2) and consists of cerium (Ce), oxygen (O), and platinum (Pt).

Figure: Gänzler/KIT

It is based on the interaction between platinum and the cerium oxide carrier to control catalytic activity by short-term changes of the engine's operation mode, researchers report in the journal Angewandte Chemie (Applied Chemistry).

Thanks to its good catalytic properties, platinum is often applied in catalytic converters of vehicles. Presently, about 60% of European platinum trade are used for this purpose. Using a diesel oxidation catalytic converter (DOC), in which afterburning of hydrocarbons and carbon monoxide takes place, the scientists of Karlsruhe Institute of Technology (KIT) and their partners found that the particle size and oxidation state of the platinum component during operation can be modified specifically.

Interactions between the carrier material and the applied noble metal play an important role. The results reflect a highly dynamic catalytic converter surface that reacts extremely sensitively to external impacts, such as exhaust gas composition. The researchers present ways of using this dynamics to improve catalytic converters.

"The special thing is that we can adjust the size and state of the noble metal nanoparticles on the surface of the catalytic converter. The methods enable us to do this under relevant and even real operation conditions and, hence, to directly adjust the catalytic activity of materials," says Andreas Gänzler, scientist of KIT's Institute for Chemical Technology and Polymer Chemistry (ITCP) and main author of the study "Tuning the Structure of Platinum Particles on Ceria In Situ for Enhancing the Catalytic Performance of Exhaust Gas Catalysts" published in the latest issue of the journal Angewandte Chemie (Applied Chemistry).

In their study, the researchers demonstrated how sensitively the state of platinum reacts to the composition, i.e. the ratio of carbon monoxide and oxygen, and the temperature of the exhaust gas. Engine operation already is modified specifically in exhaust gas aftertreatment systems used today. In this way, exhaust gas composition is adjusted for the regeneration of particulate filters or NOx storage catalytic converters. The study reveals that it is also possible to optimally set the active platinum component in order to enhance activity of the catalytic converter and reduce the consumption of noble metal.

In the course of the German-French cooperation project, complex methods were used to observe the materials under operation conditions. By means of environmental transmission electron microscopy (ETEM), structural modifications on the atomic level of the material were visualized. X-ray absorption spectroscopy at the SOLEIL synchrotron in the French St. Aubin and at the KARA Karlsruhe Research Accelerator of KIT was applied to study the processes under realistic exhaust gas conditions. "Based on these observations of catalytic converter materials under real conditions, findings can be transferred much more quickly to application," Gänzler points out.

With the help of the findings obtained, catalytic activity of diesel oxidation catalytic converters can be enhanced at low temperature. From their observations, the scientists derived a promising basic concept to specifically adjust the size and structure of platinum particles as a function of the catalytic activity required during operation. The concept can be used among others to significantly improve catalytic performance after the cold start of combustion engines and when driving in urban traffic. "The structure of the noble metal nanoparticles can be influenced by short-term modifications of the engine operation mode, for instance," Gänzler says.

Based on the findings, current and future new types of catalytic converters can be improved and their economic efficiency can be increased, as the noble metal concentration can be reduced by up to 50%. The study that is considered "one of the big highlights in catalytic converter research" by Professor Jan-Dierk Grunwaldt of ITCP meets with big interest of experts. It was carried out in the course of the project "ORCA - Oxidation/Reduction Catalytic Converter for Diesel Vehicles of the Next Generation" that is part of the Deufrako German-French research collaboration. The project is funded with EUR 960,000 by the Federal Ministry for Economic Affairs and Energy. Apart from KIT, the Institut de Recherches sur la Catalyse et l'Environnement de Lyon (IRCELYON), TU Darmstadt, the Solvay company, and Umicore AG & Co. KG, a materials technology and recycling company in Hanau, take part in the collaboration project.

###

Andreas M. Gänzler, Maria Casapu, Philippe Vernoux, Stéphane Loridant, Francisco J. Cadete Santos Aires, Thierry Epicier, Benjamin Betz, Rüdiger Hoyer, and Jan-Dierk Grunwaldt: Tuning the Structure of Platinum Particles on Ceria In Situ for Enhancing the Catalytic Performance of Exhaust Gas Catalysts. DOI: 10.1002/anie.201707842

http://onlinelibrary.wiley.com/doi/10.1002/anie.201707842/abstract

More information:

http://www.itcp.kit.edu/abgaszentrum (in German only)

More about the KIT Mobility Systems Center http://www.kit.edu/research/6720.php

For further information, please contact:

Kosta Schinarakis, Science Scout, Phone: 49-721-608-41956, Fax: 49-721-608-43658, Email: schinarakis@kit.edu

Being "The Research University in the Helmholtz Association," KIT creates and imparts knowledge for the society and the environment. It is the objective to make significant contributions to the global challenges in the fields of energy, mobility and information. For this, about 9,300 employees cooperate in a broad range of disciplines in natural sciences, engineering sciences, economics, and the humanities and social sciences. KIT prepares its 26,000 students for responsible tasks in society, industry, and science by offering research-based study programs. Innovation efforts at KIT build a bridge between important scientific findings and their application for the benefit of society, economic prosperity, and the preservation of our natural basis of life.

Since 2010, the KIT has been certified as a family-friendly university.

This press release is available on the internet at http://www.sek.kit.edu/english/press_office.php.

Monika Landgraf | EurekAlert!

More articles from Life Sciences:

nachricht A new 'cool' blue
17.01.2020 | American Chemical Society

nachricht Neuromuscular organoid: It’s contracting!
17.01.2020 | Max-Delbrück-Centrum für Molekulare Medizin in der Helmholtz-Gemeinschaft

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Miniature double glazing: Material developed which is heat-insulating and heat-conducting at the same time

Styrofoam or copper - both materials have very different properties with regard to their ability to conduct heat. Scientists at the Max Planck Institute for Polymer Research (MPI-P) in Mainz and the University of Bayreuth have now jointly developed and characterized a novel, extremely thin and transparent material that has different thermal conduction properties depending on the direction. While it can conduct heat extremely well in one direction, it shows good thermal insulation in the other direction.

Thermal insulation and thermal conduction play a crucial role in our everyday lives - from computer processors, where it is important to dissipate heat as...

Im Focus: Fraunhofer IAF establishes an application laboratory for quantum sensors

In order to advance the transfer of research developments from the field of quantum sensor technology into industrial applications, an application laboratory is being established at Fraunhofer IAF. This will enable interested companies and especially regional SMEs and start-ups to evaluate the innovation potential of quantum sensors for their specific requirements. Both the state of Baden-Württemberg and the Fraunhofer-Gesellschaft are supporting the four-year project with one million euros each.

The application laboratory is being set up as part of the Fraunhofer lighthouse project »QMag«, short for quantum magnetometry. In this project, researchers...

Im Focus: How Cells Assemble Their Skeleton

Researchers study the formation of microtubules

Microtubules, filamentous structures within the cell, are required for many important processes, including cell division and intracellular transport. A...

Im Focus: World Premiere in Zurich: Machine keeps human livers alive for one week outside of the body

Researchers from the University Hospital Zurich, ETH Zurich, Wyss Zurich and the University of Zurich have developed a machine that repairs injured human livers and keep them alive outside the body for one week. This breakthrough may increase the number of available organs for transplantation saving many lives of patients with severe liver diseases or cancer.

Until now, livers could be stored safely outside the body for only a few hours. With the novel perfusion technology, livers - and even injured livers - can now...

Im Focus: SuperTIGER on its second prowl -- 130,000 feet above Antarctica

A balloon-borne scientific instrument designed to study the origin of cosmic rays is taking its second turn high above the continent of Antarctica three and a half weeks after its launch.

SuperTIGER (Super Trans-Iron Galactic Element Recorder) is designed to measure the rare, heavy elements in cosmic rays that hold clues about their origins...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

11th Advanced Battery Power Conference, March 24-25, 2020 in Münster/Germany

16.01.2020 | Event News

Laser Colloquium Hydrogen LKH2: fast and reliable fuel cell manufacturing

15.01.2020 | Event News

„Advanced Battery Power“- Conference, Contributions are welcome!

07.01.2020 | Event News

 
Latest News

A new 'cool' blue

17.01.2020 | Life Sciences

EU-project SONAR: Better batteries for electricity from renewable energy sources

17.01.2020 | Power and Electrical Engineering

Neuromuscular organoid: It’s contracting!

17.01.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>