Navigation Links
Mysterious catalyst explained
Date:4/30/2013

From methanol to formaldehyde - this reaction is the starting point for the synthesis of many everyday plastics. Using catalysts made of gold particles, formaldehyde could be produced without the environmentally hazardous waste generated in conventional methods. Just how the mysterious gold catalyst works has been found out by theoretical and experimental researchers at the Ruhr-Universitt Bochum in a cooperation project. In the international edition of the journal "Angewandte Chemie" they report in detail on what happens on the gold surface during the chemical reaction.

"Gold should not really be suitable as a catalyst."

"That nanoparticles of gold actually selectively transform methanol into formaldehyde is remarkable", says Prof. Dr. Martin Muhler of the Laboratory of Industrial Chemistry at the RUB. "As a stable precious metal, gold should not really be suitable as a catalyst." However, gold particles of a few nanometres in size, anchored to a titanium dioxide surface, fulfil their purpose. You only need oxygen to set the reaction in motion, and the only waste product is water. How this is achieved is examined by Muhler's team together with the groups of Prof. Dr. Dominik Marx of the Chair of Theoretical Chemistry and Dr. Yuemin Wang of the Department of Physical Chemistry I.

Oxygen binds at the interface between gold and titanium dioxide

The chemists identified the active site of the catalyst, i.e. the point at which the oxygen and methanol bind and are converted to water and formaldehyde. Elaborate calculations by Dr. Matteo Farnesi Camellone showed that oxygen binds at the interface between titanium dioxide and gold particles. Since titanium dioxide is a semiconductor, and thus electrically conductive, a charge exchange between oxygen, gold particles and titanium dioxide is possible here. Oxygen vacancies in the titanium dioxide further favour this charge transfer. Electrons transitionally transfer from the catalyst to the oxygen molecule. This allows the methanol to bind to the gold particles. In several further reaction steps, formaldehyde and water form. The solid, which consists of gold and titanium dioxide, is in the same state at the end of the reaction cycle as at the beginning, and is thus not consumed.

Experiment and theory: only the combination makes it possible

The RUB team clarified the individual reaction steps in detail. The researchers used computer simulations, so-called density functional calculations, and various spectroscopic techniques, namely, vibrational spectroscopy (HREELS method) and thermal desorption spectroscopy. In his model calculations, Dr. Farnesi quantified the charge exchange taking place during catalysis. Extremely sensitive vibrational spectroscopic measurements by Dr. Wang's group confirmed the consequences of the charge transfer in the real system. "Through an intensive cooperation between theory and experiment, we have been able to qualitatively and quantitatively explore the active site and the entire reaction mechanism of this complex catalyst", stresses Prof. Marx.


'/>"/>

Contact: Dominik Marx
dominik.marx@theochem.rub.de
49-234-322-8083
Ruhr-University Bochum
Source:Eurekalert

Related biology news :

1. Astronomer gets grant to better measure mysterious black holes
2. The mysterious GRIN3A and the cause of schizophrenia
3. Researchers id queens, mysterious disease syndrome as key factors in bee colony deaths
4. Synchrotron infrared unveils a mysterious microbial community
5. Nunavuts mysterious ancient life could return by 2100
6. Mysterious snake disease decoded
7. Gene discovery set to help with mysterious paralysis of childhood
8. Life cycles of mysterious Namibian grassland fairy circles characterized
9. DNA catalysts do the work of protein enzymes
10. Catalysts that produce green fuel
11. Painting with catalysts: Nano-engineered materials for detoxifying water by use of sunlight
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/11/2016)... -- http://www.apimages.com ) - --> http://www.apimages.com ) ... AP Images ( http://www.apimages.com ) - Germany ... the new refugee identity cards. DERMALOG will be unveiling this device, ... Hanover next week.   --> Germany ... produce the new refugee identity cards. DERMALOG will be unveiling this ...
(Date:3/9/2016)... , March 9, 2016 This BCC ... future states of the RNA Sequencing (RNA Seq) market ... such as instruments, tools and reagents, data analysis, and ... various segments of the RNA-Sequencing market such as RNA-Sequencing ... Identify the main factors affecting each segment and forecast ...
(Date:3/3/2016)... 2016  FlexTech, a SEMI Strategic Association Partner, awarded ... & Development, Leadership in Education, and, in a category ... th year of the FLEXI Awards and the ... from past years . Judging was done on ... of criteria, by a panel of non-affiliated, independent, industry ...
Breaking Biology News(10 mins):
(Date:5/5/2016)... ... May 05, 2016 , ... American ... two additional patents, U.S. Patent Nos. 9,322,133 and 9,322,134, to API and its ... nanocellulose as well as hydrophobic nanocellulose compositions. In addition to these patents ...
(Date:5/5/2016)... BELL, Pa. , May 5, 2016  Why ... Powers and Lorna Weir launching a ... un-agency way? Because they believe that truly helping clients ... world of healthcare now demands a different type of ... strategy lab serving the pharmaceutical, biotechnology and medical device ...
(Date:5/5/2016)... , ... May 05, 2016 , ... ... previously announced identification of its first three targets, it has identified a fourth ... beta (Aß), implicated in the development and progression of Alzheimer’s disease (AD). ...
(Date:5/4/2016)... ... 2016 , ... CereScan, the nation’s leader in providing statistically ... Stroke Awareness Month in May. An infographic created by CereScan will be ... will donate $1 up to a maximum of $3,000 through users who share ...
Breaking Biology Technology: