Oxygen exchange on nanocrystalline tin dioxide modified by palladium

► Nanocrystalline SnO2 can exchange up to 100% of constituent oxygen with gas phase. ► Simple heteroexchange mechanism dominates for blank SnO2 interaction with oxygen. ► Pd clusters on SnO2 surface enhance oxygen exchange rate. ► Catalytic effect of Pd is due to O2 dissociation and spill-over on active clusters. ► Partial Pd deactivation occurs at elevated temperature due to morphology changes.