Credit: © 2008 Wiley

Until the late 1980s it was generally thought that gold was catalytically inert. Since then, however, gold nanoparticles with diameters of less than 5 nm have been shown to be remarkably good at a range of significant oxidation reactions, even at low temperatures, although the reasons for this have been the subject of much debate. Now, Jens Nørskov and colleagues1 at the Technical University of Denmark have compared theoretically the catalytic activity of gold with other metals to try to understand the origins of its catalytic properties.

Using density functional theory, Nørskov and colleagues modelled the reaction pathway of CO oxidation on nanoparticles and extended metal surfaces. They found that the high catalytic activity of gold nanoparticles could be related to the increased number of low-coordinate 'corner atoms' that are created as the size of the metal particle is reduced.

Because the effects of the material supporting the gold — which are usually considered to play an important role in its catalytic properties — were not taken into account in the calculations, the results suggest that gold itself has intrinsic catalytic properties.