Catalytic enhancement of gold nanocages induced by undercoordination-charge-polarization

Principle behind the highest catalytic ability of the least coordinated gold remains a puzzle. With the aid of density functional theory calculations, we show that in 3-coordinated gold cages (i) the Au–Au bond contracts by ∼5% in average, (ii) the valance density-of-states shift up to Fermi level when the Au55 cluster turns into an Au12 cage, and (iii) the activation energy for CO oxidation drops in sequence, Au55 cluster (13.6 Kcal/mol), Au42 cage (8.0 Kcal/mol), Au13(6.5 Kcal/mol), and Au12 cage (5.1 Kcal/mol), with comparing the reaction paths and spin states. The principle clarified here paves the way for the design of gold nanocatalyst.