Spectroscopic evidence for a CO–O2 complex as a precursor to the low temperature oxidation of CO on the Pt(111) surface

Reflection absorption infrared spectroscopy was used to study the reaction of adsorbed molecular oxygen with carbon monoxide to produce adsorbed carbon dioxide at 130 K. By simultaneously monitoring the O–O stretch of O 2 (ads), the C–O stretch of CO(ads), and the asymmetric O–C–O stretch of CO 2 (ads), it is found that there is an O 2 –CO interaction, suggesting that the transition state involves direct transfer of an O atom from O 2 (ads) to CO, rather than through reaction of CO(ads) with a hot surface O atom produced from O 2 dissociation.