Navigation Links
KIT: Processes at the surface of catalysts
Date:4/10/2012

This release is available in German.

In chemical industry, heterogeneous catalysis is of crucial importance to the manufacture of basic or fine chemicals, in catalytic converters of exhaust gas, or for the chemical storage of solar energy. Scientists of Karlsruhe Institute of Technology (KIT) and Ruhr-Universitt Bochum (RUB) have developed a new infrared spectroscopy method in order to study processes at surfaces of oxides used as catalysts. Their results are published in the renowned Angewandte Chemie journal.

Catalysts support many chemical reactions. In heterogeneous catalysis, the substance used as a catalyst and the reacting substances exist in various phases. Usually, the catalyst is a solid, while the reacting substances are gaseous. At the surface of catalytically active solids, highly complex chemical processes take place. They have to be understood in detail in order to further improve products and reduce costs. The processes are known well for metals. However, conversions at the surface of oxides compounds of metals or nonmetals with oxygen have hardly been studied so far.

The research team of Professor Christof Wll from KIT and Professor Martin Muhler from RUB first studied processes at surfaces of oxide monocrystals and then transferred the findings to powders, the technically most important form of oxide materials. Doing this, they were the first to bridge the gap between fundamental research into reference systems and applied research into real catalysts. A newly developed combination device for infrared spectroscopy (IR) allows for highly precise measurements of the vibration frequency of carbon monoxide. The exact value of this vibration frequency is highly sensitive to defects.

Such defects result from the removal of individual oxygen atoms from oxide materials. "Oxygen defects act as active centers and give the material a high catalytic activity," explains Professor Christof Wll, Director of the Institute of Functional Interfaces (IFG) of KIT. With the new combination device for infrared spectroscopy, the researchers from Karlsruhe and Bochum developed a method that was first calibrated for reference systems. For the first time, they then measured defect densities of real catalyst powders using a high-performance FTIR spectrometer made by Bruker Optics (VERTEX series).

To demonstrate their new method, the researchers used rutile, the most important modification of titanium dioxide (TiO2). "This material used as white pigment and in photocatalysis normally is chemically highly inert and rendered catalytically active by the oxygen defects only," explains Professor Christof Wll. Professor Martin Muhler from RUB points out that such defects in powder materials have only been detected indirectly so far.

With their method, the researchers, including Dr. Mingchun Xu, Dr. Heshmat Noei, and Dr. Yuemin Wang from RUB as well as Dr. Karin Fink from the Institute of Nanotechnology (INT) of KIT, followed the "Surface Science" approach developed by the Noble Prize laureate Gerhard Ertl. They demonstrated the potential of their method by studying the carbon-carbon coupling reaction of formaldehyde to ethylene. Doing this, it was confirmed that the density of oxygen defects at the surface of r-TiO2 nanoparticles is of decisive im-portance to the catalytic activity of the oxide powder and, hence, to the yield.


'/>"/>

Contact: Monika Landgraf
presse@kit.edu
49-721-608-47414
Helmholtz Association of German Research Centres
Source:Eurekalert  

Related biology news :

1. Advancing next gen biofuels by turning up the heat on biomass pretreatment processes
2. Processes for obtaining ecological compound that can optimize biodiesel enhanced
3. Breaking the chain: Molecular cap blocks processes that lead to Alzheimers, HIV
4. The gene processes that drive acute myeloid leukaemia
5. Particulate Processes in the Pharmaceutical Industry III
6. Communication engages complex brain circuitry and processes
7. Creating new healthy ingredients by innovative milling techniques and processes for cereal grains
8. New studies reveal downstream processes of ion channel inactivation
9. Laser processes promise better artificial joints, arterial stents
10. Powerful new molecular GPS helps probe aging and disease processes
11. Microfluidic palette may paint clearer picture of biological processes
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
KIT: Processes at the surface of catalysts
(Date:4/6/2017)... , April 6, 2017 ... RFID, ANPR, Document Readers, by End-Use (Transportation & Logistics, ... Facility, Oil, Gas & Fossil Generation Facility, Nuclear Power), ... Educational, Other) Are you looking for a ... sector? ...
(Date:4/5/2017)... April 5, 2017 Today HYPR Corp. ... the server component of the HYPR platform is officially ... the end-to-end security architecture that empowers biometric authentication across ... has already secured over 15 million users across the ... of connected home product suites and physical access represent ...
(Date:4/4/2017)... April 4, 2017   EyeLock LLC , a ... the United States Patent and Trademark Office (USPTO) has ... the linking of an iris image with a face ... represents the company,s 45 th issued patent. ... very timely given the multi-modal biometric capabilities that have ...
Breaking Biology News(10 mins):
(Date:5/19/2017)... ... May 19, 2017 , ... In response to the ... disorders, Biodex Medical Systems, Inc. announces the release of their Gait Trainer 3 with ... joined with a biomedical system to aid in rehabilitating individuals with cerebral palsy, traumatic ...
(Date:5/18/2017)... ... May 18, 2017 , ... Lajollacooks4u has ... Challenge is a two-hour team-building package designed for groups of 10-30 people. ... Abel, which include items, such as Blackened Shrimp with Edamame Salad, Pizza Rolls ...
(Date:5/18/2017)... ... May 17, 2017 , ... ... and further enhances its scientific power by providing investigators access to a ... agreed to join the scientific advisory board. “We are committed to offering ...
(Date:5/18/2017)... ... May 17, 2017 , ... HOLLOWAY AMERICA, ... including food and dairy, munitions, and pharmaceutical/biotech, recently introduced The Revolution Lift™, a ... use. The improvement in technology comes on the heels of HOLLOWAY’s release of ...
Breaking Biology Technology: