Oxidation of carbon monoxide on small iron clusters

The oxidation of carbon monoxide adsorbed on Fen (n=1–6) clusters is studied using density functional theory. Both neutral and anionic clusters are studied. The reactions of chemisorbed CO with O2 are found to be highly exothermic for all of the iron clusters considered. Effects of higher coverages are estimated using the Fe4 cluster with two adsorbates, namely Fe4(CO)2, Fe4C2, and Fe4O2 clusters. Our results suggest that the iron clusters sustain a full catalytic cycle of carbon monoxide oxidation.