CO and H2O adsorption and reaction on Au(310)

► Complete and Redhead analyses of CO desorption spectra from Au(310) are inconsistent. ► H2O displaces CO pre-adsorbed at step sites, but does not react to form CO2. ► In combination with electron irradiation, CO and H2O react to CO2. ► Oads or OHads seem sheltered by hydration from direct reaction with CO.