Reactive scattering of CO from an oxygen-atom-covered Au/TiO2 model catalyst

We present results of a reactive scattering study of CO from an oxygen-atom-covered Au/TiO2 model catalyst. We studied the CO oxidation reaction with preadsorbed atomic oxygen over a surface temperature range from 65 to 250 K and observed CO2 production at all temperatures studied from the gold-covered titania samples. No reaction is observed on the bare TiO2 (i.e., no gold) at any of the temperatures studied. The CO oxidation reaction is observed to proceed on all gold coverages studied (0.25-30 ML) as well as on a nominally continuous gold film. Hence, we conclude that the reaction of an oxygen atom with CO is relatively particle size independent and even independent of the TiO2 support and therefore not exclusive to the gold-titania interface, if oxygen atoms are preadsorbed prior to CO exposure.