Tailoring of the Proximity of Platinum Single Atoms on CeO₂ Using Phosphorus Boosts the Hydrogenation Activity

Atomically dispersed metal atoms on supports, so-called single-atom catalysts (SACs), have recently attracted extensive attention in the catalysis field. It has been found that besides the primary metal atom, the proximial atoms also contribute to the catalytic activity significantly. Here, we show that tailoring of the local coordination environment of Pt₁ single atoms on CeO₂ using phosphorus gives rise to an activity enhancement up to a 10 times higher than Pt₁/CeO₂ SAC in hydrogenation of styrene, cyclohexene, phenylacetylene, and nitrobenzene. X-ray absorption, photoelectron, and infrared spectroscopies showed that the Pt₁ single atoms modulated by phosphorus have a higher valence state. Infrared spectroscopy and temperature-programmed reduction further unveiled that significantly stronger adsorption of reactant and facilitated hydrogen spillover on phosphorus-doped CeO₂ both play important roles for the dramatic activity enhancement. These findings point out an avenue to design an advanced SACs with high activity.