DFT+U calculations of CO oxidation by Au12 nanoclusters supported on a stepped-CeO2(111) surface show that lattice oxygen at the step edge oxidizes CO bound to Au NCs by the Mars-van Krevelen (M-vK) mechanism. We found that CO2 desorption determines the rate of CO oxidation, and the vacancy formation energy is a reactivity descriptor for CO oxidation. Our results suggest that the M-vK mechanism contributes significantly to CO oxidation activity at Au particles supported on the nano- or meso-structured CeO2 found in industrial catalysts.
Keywords: ceria; density functional calculations; gold catalysis; interface; reaction mechanism.