A US research team has developed single site catalysts with ruthenium and platinum coatings which it claims could overcome some of the difficulties associated with hydrogen production for use in fuel cells.

The team, from the US Department of Energy's Argonne National Laboratory, used single site catalysts, based on ceria or lanthanum chromite doped with either platinum or ruthenium, to boost production at lower temperatures during reforming.

According to Michael Krumpelt, who led the research, the new, small catalysts are able to produce hydrogen more efficiently due to the use of single atomic sites imbedded in an oxide matrix. This reduces the clogging that inhibits the process in larger devices, which are ordinarily formed from metal grains tens of thousands of atoms in diameter that speckle the surface of metal oxide substrates.

Dr Krumpelt found that the best results were attained when he substituted ruthenium for platinum, which tended to become unstable at higher temperatures. However, when using ruthenium-coated catalysts, he found he could initiate reforming at 450 degrees C, while retaining good thermal stability.

The crystalline structure of the catalysts' perovskite lattice also functions to protect the ruthenium catalyst from deactivation by sulphur, Dr Krumpelt claims.

Source:

New catalysts may create more, cheaper hydrogen, 20/08/07
http://www.anl.gov/Media_Center/News/2007/news070820.html

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