The role of polaronic states in the enhancement of CO oxidation by single-atom Pt/CeO2

Single Atom Catalysts (SACs) have shown that the miniaturization of the active site implies new phenomena like dynamic charge transfer between isolated metal atoms and the oxide. To obtain direct proof of this phenomenon is challenging, as many experimental techniques provide averaged properties or have limitations with poorly conductive materials, leaving kinetic measurements from catalytic testing as the only reliable reference. Here we present an integrated Density Functional Theory-Microkinetic model including ground and high-energy metastable states to address the reactivity of Pt1CeO2 for CO oxidation. Our model agrees with experimentally available kinetic data showing that CO oxidation activity of Pt1/CeO2 is tunable via the electronic properties of the support. Particularly, samples with higher n-doping via oxygen depletion should be better in CO oxidation, as they help maintain the active state Pt^0 of the catalyst. This provides a general route to improve low-temperature oxidations at metal/oxides interfaces via charge transfer control.