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:12/15/2016)... , Dec. 15, 2016 Advancements ... experience, health wellness and wellbeing (HWW), and ... in three new passenger vehicles begin to ... gesture recognition, heart beat monitoring, brain wave ... facial monitoring, and pulse detection. These will ...
(Date:12/12/2016)... 12, 2016  Researchers at Trinity College, Dublin, ... by combining the material with Silly Putty. The mixture ... detector able to sense pulse, blood pressure, respiration, ... The research team,s findings were ... here:  http://science.sciencemag.org/content/354/6317/1257 ...
(Date:12/7/2016)... , December 7, 2016 According to a new ... Learning), Software Tool (Facial Expression, Voice Recognition), Service, Application Area, End User, And ... estimated to grow from USD 6.72 Billion in 2016 to USD 36.07 Billion ... Continue Reading ... ...
Breaking Biology News(10 mins):
(Date:1/11/2017)... ... 11, 2017 , ... Photonics industry and STEM advocates associated ... the U.S. Congress and President Obama for their recognition of the importance of ... Innovation and Competitiveness Act (AICA). , The language of the act (S. 3084) ...
(Date:1/11/2017)... Yorba Linda, Ca (PRWEB) , ... January 11, ... ... antibiotic resistance in pathogens are observed in clinical settings, it is becoming increasingly ... ecological problem. An over-reliance on culture-based methods, the standard in the study of ...
(Date:1/11/2017)... ... January 11, 2017 , ... For many fledging ... navigating the challenges young businesses face. With the second installment of Quorum’s newest ... of Geoff DiMasi, Founder and Principal of interactive design agency, P’unk Ave. ...
(Date:1/11/2017)... Orleans, La. (PRWEB) , ... January 11, 2017 ... ... a European business development professional has joined its team. Bernhard Bartylla will lead ... , “We’re working with Bernhard to introduce ACOMP and ARGEN to European manufacturers ...
Breaking Biology Technology: