Theoretical Insight into the Mechanism and Descriptor for Hydrogen Spillover on the Pt/CeO2(111) Surface with Different Pt Coverages

Hydrogen spillover, as a common phenomenon, pervasively occurs in heterogeneous catalysis. Nevertheless, the understanding of the dynamic mechanism of hydrogen spillover in the typical Pt/CeO2 system remains limited. Herein, the pathways for hydrogen spillover on the surface of two Pt/CeO2(111) models have been systematically investigated using density functional theory (DFT) calculations. Hydrogen coverage and metal coverage are considered factors influencing hydrogen spillover in the Pt/CeO2 system. Descriptors for hydrogen migration at different metal coverages have been proposed to screen effective spillover metals within group Ⅷ: at lower metal coverages, the difference between [Eads(M−H)] and [Eads(O−H)] is considered as a descriptor, at higher metal coverages, the [Eads(M−H)] is used as a descriptor. Based on hydrogen spillover pathways, two dynamic mechanisms of hydrogen spillover, namely M–O–M and M–M, are introduced at different metal coverages. This study offers a deeper understanding of the hydrogen spillover phenomenon, proposes descriptors for hydrogen spillover and provides new insights into the design of heterogeneous catalysts.