Origins of Less Noble Behavior by Au during CO Adsorption

The behavior of the CO interaction with gold in an electrochemical environment is presented in this work by means of the SERS technique. The results show spectroscopic evidence that the adsorbed CO promotes the formation of oxidic species even at potentials where it is not thermodynamically favorable (lower than 0.6 V vs RHE), explaining the low-overpotential CO electrooxidation reaction onset (@ ca. 0.2 V). At high potentials (<1.3 V), the CO displays an anomalous behavior, persisting adsorbed on the surface at the high coverage oxide film, which allows us to use the CO molecule as a probe and get information about the electrode surface on the course of the reaction as well as suggests gold oxide to be an active catalyst in small organic alcohol oxidation.