June 24, 2010
Scientists Show The Way To A More Effective Creation Of Hydrogen
Energy from hydrogen "“ scientists from all over the world work on this solution to overcome the energy crisis. Amongst other things they try to use the sunlight as driving force for the splitting of water into hydrogen and oxygen. In trying to copy the photosynthesis in the laboratory a team of scientists of the Universities of Jena and Erlangen-Nrnberg and of the Institute of Photonic Technology (IPHT) in Jena (Germany) made a huge step forward. The physicists and chemists were able to prove in their tests, that the first step already affects the efficiency of hydrogen generation. "This is as if you would decide about where youÃ´re going to by turning the ignition key in the car," says PD Dr Michael Schmitt from the Institute of Physical Chemistry (IPC) of the University of Jena. To put it scientifically: "The Franck-Cordon-point has to be created in such a way that the initial process of transferring electrons already points into the direction of the catalytic active centre." The results were published in the science journal "Angewandte Chemie Int. Ed.".
In their tests for a more efficient energy conversion the scientists focus on chemical photo catalysts. With this light is being used to let electrons "jump" well-directed from one subunit of the molecule to the other or to transport them over a ligand, which is a "bridge".
"This knowledge enables us to put up well-directed barriers so that the electrons donÃ´t take a ,wrong turn' but exclusively end up at the Palladium", says Prof Popp explaining the application potential of this fundamental research. In the laboratory the hydrogen generation is four times above former data but still far below the necessary rate. Now it is up to the chemists, like the participating Prof. Dr Sven Rau, to optimize the molecular catalysts, that "no electrons will be taken on by terminal ligands," as Schmitt explains.
The scientists know that it is still a long way to go to copy the photosynthesis of nature correctly and efficiently. "But due to our spectroscopic analysis we took a huge step on this way", Prof Popp is sure though.
Reference: Stefanie Tschierlei, Michael Karnahl, Martin Presselt, Benjamin Dietzek, Julien Guthmuller, Leticia González, Michael Schmitt, Sven Rau und Jrgen Popp: "Photochemisches Schicksal:"Å¾Photochemical Fate: The First Step Determines Efficiency of H2 Formation with a Supramolecular Photocatalyst", Angew. Chem. Int. Ed. 2010, 122, 3981-3984.
Image Caption: These are scientists Dr. Stefanie Tschierlei and Dr. Michael Schmitt working in a spectroscopy laboratory of Jena University. Credit: FSU
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