Scientists from the US Department of Energy's Brookhaven National Laboratory say they are developing the role ruthenium plays in the production of ammonia.

Ruthenium catalysts can boast reactivity rates in the process that makes ammonia by as much as a factor of ten in comparison with other metals, but are not frequently used because they do not remain active long enough.

Determining a way to produce ammonia more quickly is, however, becoming a priority - with the chemical the fifth most abundantly produced in the US.

The Brookhaven scientists told the Journal of the American Chemical Society they have gone some way to achieving this after scrutinising the role ruthenium plays in the process.

The key is finding the optimum 'surface' that the ruthenium sits on in the process - at present this is done using an 'activated' carbon support, a porous graphite with a layered, crystalline structure. However, this surface is unstable, with the catalyst itself slowly becoming consumed.

Now the team are studying how a graphite support affects the structure and reactivity of the ruthenium particles and have determined their atomic structure. This key information - that the ruthenium particles have a high density of 'active sites' and that they are built in layers -is already yielding results as Zhen Song, the study's lead scientist, explained.

'These results tell us that scientists should look for a support that encourages the epitaxial growth of flat, layered ruthenium particles like these, in order to find an alternative to activated carbon,' said Song. 'Particles with these features are efficient catalysts.'

The research group says it will continue investigating ruthenium catalysts in an effort to refine the process.