Design of Stable Ultrasmall Pt-Ni(O) Nanoparticles with Enhanced Catalytic Performance: Insights into the Effects of Pt-Ni-NiO Dual Interfaces

Noble metal/transition metal oxide interfaces are typically considered as highly active sites for most heterogeneous catalytic reactions and can effectively increase the utilization of noble metals. One of the challenges in such catalytic systems, particularly under high-temperature reactions, is the lack of an effective strategy to stabilize the catalysts against sintering over time and maintain the metal/oxide interfaces. We developed a one-pot facile strategy to embed the ultrafine Pt-Ni(O) nanoparticles (NPs) with dual interfaces (Pt-Ni-NiO) in a microporous silica shell to fabricate a high-performance heterogeneous oxidation catalyst (assigned as Pt-Ni(O)@SiO2) for the first time. Owing to the ultra-small size of the Pt-Ni(O) NPs and the confinement effect of the silica shell, the resulting Pt-Ni(O)@SiO2 catalyst exhibited enhanced performance for CO oxidation and toluene [one of the main volatile organic compounds, (VOCs)] total combustion. The effects of Pt-NiO, Pt-Ni-NiO, and Pt-Ni interfaces were also studied in detail. The results indicated that the Pt-NiO and Pt-Ni alloy dual interface have the improving effect for catalytic oxidation and reducing utilization of noble metals. The strategy developed in this work may represent a general approach in the rational design of other high-performance catalysts combining the interface catalysis and physical confinement concept to improve the usage of the noble metals.