The Journal of Young Investigators: An Undergraduate, Peer-Reviewed Science Journal

25 November 2004 - Researchers from Emory University have created a molecule with multiple stable chemical bonds between oxygen and platinum, an achievement once thought to be impossible. The accomplishment, recently accepted for publication in the journal Science, may have tremendous applications for fuel cells, catalytic converters, and ‘green’ chemistry.

Chemists have long doubted that certain transition metals, such as nickel, palladium, and platinum, could support the binding of a group of oxygen atoms in a stable molecular complex. Metal-oxo species, those with chemical bonds between metals and oxygen, become increasingly unstable towards the right side of the periodic table of elements because of the repulsion between the oxygen electrons and the outermost electron orbitals of the metals. Until this work at Emory, previous attempts to create metal-oxo species with elements such as gold, platinum, silver, iridium, and rhodium have been unsuccessful.

Metallic platinum is an excellent catalyst for oxidation of organic carbon-based compounds. O2-based organic oxidations could theoretically generate fewer inorganic by-products, work under less hazardous conditions, allow easy separation of products, and generate less waste. The platinum-oxo species could be an important intermediate in these oxidations.

“It is very exciting that we were able to create a metal-oxo compound with platinum since it is an excellent catalyst for environmentally friendly processes,” says Travis Anderson, the lead researcher for the project.

The new platinum-oxo unit may be important in the improvement of fuel cells, electrochemical devices that continuously change chemical energy of a fuel and oxygen directly to electrical energy and heat without combustion. Fuel cells are quiet, give off very few emissions, and are at least twice as efficient as gasoline engines. The cells can power motor vehicles, heat buildings, and generate electricity. Because the electrodes in these fuel cells are frequently based on platinum or the reaction of platinum with oxygen, the stable platinum-oxo unit may have tremendous applications to fuel cell development.

“Since this metal-oxo [compound] is a unique compound, both its physical properties and its chemical reactivities should provide new insights and break new ground,” says principal investigator Craig Hill, Goodrich C. White Professor of Chemistry at Emory.
Now that the researchers at Emory have succeeded in synthesizing a platinum-oxo compound, they hope to create similar metal-oxo bonds with other elements near platinum on the periodic table.

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