Cryogenic CO oxidation on TiO(2)-supported gold nanoclusters precovered with atomic oxygen

Bulk gold has long been regarded as a noble metal, having very low chemical and catalytic activity. However, metal oxide-supported gold particles, particularly those that are less than 5 nm in diameter, have been found to have remarkable catalytic properties. In this study we show that impinging gas-phase CO molecules react readily with oxygen adatoms preadsorbed on Au/TiO(2)(110) to produce CO(2) even under conditions in which the sample is cryogenically cooled. Gold particle size seems to have little effect on the CO oxidation reaction when oxygen adatoms are preadsorbed. We also show that as the oxygen adatom coverage increases, the rate of CO oxidation decreases on Au/TiO(2) at cryogenic temperatures.