Over 80 % of the worlds energy demands continue to be met with fossil fuels. The environmental problems associated with this, such as global warming, are well-known. The efficient supply of energy based on renewable resources is becoming more pressing.
Hydrogen technology, which involves the production of hydrogen from biomass for use in electricity production in fuel cells, is a very promising approach. In the journal Angewandte Chemie, researchers led by Matthias Beller at the Leibniz Institute for Catalysis in Rostock (Germany) have now introduced a new catalyst that allows for the use of bioalcohols for the production of hydrogen. Their novel process proceeds efficiently under particularly mild conditions.Ethanol and other alcohols do not willingly give up their hydrogen atoms; this type of reaction requires highly active catalysts. Previous catalytic processes require downright drastic reaction conditions: temperatures above 200 °C and the presence of strong bases. The Rostock researchers thus aimed to develop a catalyst that would also work efficiently at significantly milder temperatures.
Martin Nielson, working on Beller’s team thanks to an Alexander von Humboldt scholarship, has now been successful.
The new catalyst demonstrates previously unachievable high efficiency in the extraction of hydrogen from alcohols under mild reaction conditions. Says Beller, “This is the first catalytic system that is capable of obtaining hydrogen from readily available ethanol at temperatures under 100 °C without the use of bases or other additives.”
After initial successful tests with a relatively easily converted model alcohol (isopropanol), the researchers turned their attention to ethanol, also known as the “alcohol” in alcoholic beverages. Ethanol has taken on increasing importance as a renewable resource but is significantly harder to convert. “Even with ethanol, this new catalyst system demonstrated an unusually good conversion rate under milder conditions (60–80 °C),“ says Beller. “In comparison to previous catalyst systems, this one is nearly an order of magnitude higher.”
The active catalyst consists of a ruthenium complex that is formed in situ. The starting point is a central ruthenium atom that is surrounded by a special ligand that grasps it from three sides. The other ligands are a carbon monoxide molecule and two hydrogen atoms. Upon heating, a hydrogen molecule (H2) is released from the complex. When the remaining complex comes into contact with ethanol or isopropanol it grabs two replacement hydrogen atoms, allowing the cycle to begin again.Author: Matthias Beller, Leibniz-Institut für Katalyse an der Universität Rostock (Germany), http://www.catalysis.de/Beller-Matthias.239.0.html
Angewandte Chemie International Edition 2011, 50, No. 41, 9593–9597, Permalink to the article: http://dx.doi.org/10.1002/anie.201104722
Matthias Beller | Angewandte Chemie
Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University
How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy