Origin of unusual catalytic activities of Au-based catalysts

Experimental evidences for the non-dissociative chemisorption of O2 are presented on even-numbered free Au anion clusters (Aun−, n=number of atoms) up to Au20− at room temperature. Our result indicates that the formation of the activated di-oxygen species is the key of the unusual catalytic activities of Au-based catalysts. No correlation between geometrical structures of Aun− and the activities towards O2 adsorption was found, showing that site-specific chemistry disappears for Au-nanocatalysis. We demonstrate that interplay between cluster physics and surface chemistry is a promising strategy to unveil mechanisms of elementary steps in nanocatalysis.