Nanostructured Pt-CeO2 thin film catalyst grown on graphite foil by magnetron sputtering

► The Pt-CeO2 catalyst sputtered on graphite shows highly porous surface morphology. ► The Ce3+/Ce4+ and Pt2+/Pt4+ ratios are affected by plasma-substrate interaction. ► Oxygen-carbon interaction is responsible for Pt-CeO2 reduction at the interface. ► The oxygen atoms interact with the carbon surface forming CO and CO2 molecules.