Oxygen electroreduction catalyzed by gold nanoclusters: strong core size effects.

Bigger isn't better: Gold nanoclusters exhibit enhanced electrocatalytic activity in oxygen reduction when the core size decreased from Au(140) to Au(11), as reflected by the onset potential E(onset) and peak current density J(K) (see picture). The increasing fraction of surface atoms with low coordination numbers and the shift of the d-band center to the Fermi level facilitate oxygen adsorption.