March on, Hydrogen! Mild but very efficient: new catalytic process extracts hydrogen from bioalcohols

Sep 28, 2011

(PhysOrg.com) -- 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 , researchers led by Matthias Beller at the Leibniz Institute for 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 ; 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.

Explore further: New CMI process recycles magnets from factory floor

More information: Matthias Beller, Efficient Hydrogen Production from Alcohols under Mild Reaction Conditions, Angewandte Chemie International Edition 2011, 50, No. 41, 9593–9597, dx.doi.org/10.1002/anie.201104722

Related Stories

Renewable Raw Materials

May 29, 2006

Petroleum and natural gas reserves are getting smaller and smaller. It is thus a real waste to burn up these valuable resources for heat or transportation especially as "black gold" is also the most important starting material ...

Recommended for you

New CMI process recycles magnets from factory floor

6 hours ago

A new recycling method developed by scientists at the Critical Materials Institute, a U.S. Department of Energy Innovation Hub led by the Ames Laboratory, recovers valuable rare-earth magnetic material from ...

Chemists characterize 3-D macroporous hydrogels

10 hours ago

Carnegie Mellon University chemists have developed two novel methods to characterize 3-dimensional macroporous hydrogels—materials that hold great promise for developing "smart" responsive materials that ...

Substrates change nanoparticle reactivity

15 hours ago

(Phys.org)—Nanoscale materials tend to behave differently than their bulk counterparts. While there are many theories as to why this happens, technological advances in scanning tunneling microscopy (STM) ...

Reviving cottonseed meals adhesives potential

18 hours ago

Cottonseed meal—the leftovers after lint and oil are extracted from cottonseed—is typically fed to ruminant livestock, such as cows, or used as fertilizer. But Agricultural Research Service scientists ...

New concrete composite can heal itself

18 hours ago

In the human body, small wounds are easily treated by the body itself, requiring no further care. For bigger wounds to be healed, the body may need outside assistance. Concrete is like a living body, in that ...

Actuators that mimic ice plants

19 hours ago

Engineers developing moveable robot components may soon take advantage of a trick plants use. Researchers at the Max Planck Institute of Colloids and Interfaces in Potsdam and Harvard University in Cambridge ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.