New material could enable future energy technologies

Materials containing atoms that can switch back and forth between multiple oxidation states are technologically important but very rare in nature, said Oak Ridge National Laboratory’s (ORNL) Ho Nyung Lee, who led the international research team that published its findings in Nature Materials.

‘Typically, most elements have a stable oxidation state, and they want to stay there,’ Lee said in a statement. ‘So far there aren’t many known materials in which atoms are easily convertible between different valence states. We’ve found a chemical substance that can reversibly change between phases at rather low temperatures without deteriorating, which is a very intriguing phenomenon.’

According to ORNL, a Tennessee-based laboratory that is part of the US Department of Energy, many energy storage and sensor devices rely on this valence-switching, a process known as a reduction-oxidation (redox) reaction. Catalytic gas converters use platinum-based metals to transform carbon monoxide into non-toxic gases by adding oxygen. Less expensive oxide-based alternatives to platinum usually require very high temperatures - at least 600 to 700 degrees Celsius - to trigger the redox reactions, making such materials impractical in conventional applications.