CO oxidation on rough Au thin films grown on Si wafer

The CO oxidation reactivity of rough Au thin films containing ∼5% W was investigated. At room temperature, no CO oxidation could be detected under our experimental conditions, whereas conversion of CO to CO₂ was observed at 160 °C. At higher temperatures, the initial reactivity increased. However, with increasing reaction time, it was evident that deactivation of the catalytically active sites was more facile at higher temperatures. Temperature-programmed desorption (TPD) suggested that the formation of strongly bound carbonate species could be responsible for the deactivation process. Based on the TPD data, we propose that decomposition of carbonate species on the surface is the rate-determining step of CO oxidation.