The AITD analysis of the obtained global minima has revealed that oxidized particles are stable over a rather wide range of 𝜇 𝑂 . Although the CeO2(111) surface has a slightly oxidizing effect, it generally does not stabilize states with lower oxidation states. This is related to the fact that O atoms from the CeO2(111) have a much weaker oxidizing effect than O atoms directly on the PtOx clusters, as revealed by a detailed charge analysis.