Oxygen-precovered Au

Adsorption and Reaction of CO and CO2. The clean and oxygen-precovered Au(lll) surface does not chemisorb CO at temperatures down to 100 K. This was established by CO uptake experiments utilizing XPS and TPD. C(ls) and 0(ls) XPS spectra taken after a 10 L CO exposure to Au(lll) with O = 0 0/ 0.5 and 1.0 at 100 K showed no evidence for a new carbon-containing surface species, i.e., no adsorbed CO, CO2, or carbonate species is stable on the Au(lll) surface under these conditions. The area of the 0(ls) peak after CO exposure was slightly smaller for both oxygen precoverages, but this is attributed to background CO oxidation and the formation of CO2 which desorbs from the surface at 100 K (vide infra). 

Adsorption of H2O and the 0(a) + H2O interaction. H2O is a product of many oxidation reactions and its interaction with these surfaces is important to understand. We have studied water adsorption on clean and oxygen precovered Au(lll) using principally TPD and XPS, and these results are summarized below. 

Figure 4. NO2 TPD spectra after 3.2 L NO2 exposure on oxygen-precovered Au(lll) at 100 K.

Figure 8. TPD spectra following the adsorption of 0.2 L CH3OH on oxygen-precovered Au(lll) at 95 K with 0q = 0.25 (left panel) and o = 1.0 (right panel).

Schroder, J., Gunter, C., Hwang, R. Q., and Behm, R. J. (1992). A comparative STM study of the growth of thin Au films on clean and oxygen-precovered Ru(OOOl) surfaces. Ultramicroscopy 42-44, 475-482. 

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