The effect of single pd atoms on the energetics of recombinative O2 desorption from Au(111)

Abstract The oxidation of gold is an important step in a number of catalytic reactions and the oxidation of Au(111) with ozone has been well-studied using surface science techniques. We report that the addition of 1% Pd in the surface in the form of a Pd/Au(111) single-atom alloy dramatically alters the desorption temperature of molecular oxygen after oxidation by ozone. We use temperature programmed desorption to study the desorption kinetics and scanning tunneling microscopy to compare the structure of the oxides produced on Au(111) with and without 1% Pd. Aided by density functional theory we hypothesize that the lower temperature evolution of O 2 occurs not because Pd atoms lower the O 2 desorption barrier, rather than the 1% Pd disrupts the formation of the more stable 2D ordered oxide formed on Au(11). This effect is particularly pronounced when the single-atom alloy surface is treated with ozone at lower temperatures.