Supported gold catalysts: new properties offered by nanometer and sub-nanometer structures

Nano-sized gold particles on solid supports offer unexpected catalytic properties, with new discoveries emerging rapidly for oxidation, hydrogenation, coupling, and other reactions. Oxidation of H₂ to give H₂O₂ catalyzed by metal oxide-supported gold nanoclusters (reported in Chem. Commun. in 2002 by the group of Hutchings) offers promise for large-scale application. Catalysis by gold has become a vibrant, expanding field marked by continuing surprises, but fundamental understanding of how these catalysts work is emerging only slowly.