CO oxidation mechanism on the γ-Al₂O₃ supported single Pt atom: First principle study

Highlights: • DFT studied on CO oxidation mechanism on Pt/γ-Al₂O₃ catalyst. • DFT studied on the adsorption properties of single Pt on Pt/γ-Al₂O₃ catalyst. • Pt adsorptions on the Al-terminated surface are more favorable than the ones on the O-terminated surface. • The reactive O*−O−C*=O intermediate mechanism is the dominant reaction pathway for CO oxidation on Pt/γ-Al₂O₃. - Abstract: Understanding the role of metal-support interaction for the supported single-atom catalysts is very important in heterogeneous catalysis. Here, Three different CO oxidation mechanisms on Pt/γ-Al₂O₃ catalyst were probed by periodic density functional theory (DFT) calculations in detail, namely the reactive O*−O−C*=O intermediate mechanism, the reactive CO₃ intermediate mechanism and the Pt-Al³⁺ double sites mechanism. According to the calculated results analysis, we concluded that the dominant reaction pathway at the low temperatures is the reactive O*−O−C*=O intermediate mechanism. Our results are in very good agreement with the experimental evidence for O*−O−C*=O coverage on Pt/γ-Al₂O₃ at room temperature by an in situ diffuse reflectance infrared detector.