Impact of Pt-CeO₂ interface on oxidation and reduction performance of NSR catalysts

• NO oxidation capacity depends on Pt dispersion and particle size. • NO x reduction efficiency is enhanced by Pt–CeO₂ interfacial electronic modulation. • Pt–CeO₂ interfaces stabilize Pt dispersion, enhancing NSR catalyst durability. • Triple anchoring mechanism at Pt–CeO₂ interface effectively inhibits Pt sintering. NO x storage reduction (NSR) catalysts are among the most promising aftertreatment technologies for lean-burn gasoline engines, yet the role of interfacial effects in governing redox performance remains underexplored. In this study, Pt/Al₂O₃ and Pt/CeO₂/Al₂O₃ catalysts prepared by impregnation were investigated using ICP, TEM, XRD, CO chemisorption, XPS, H₂-TPR, and Raman spectroscopy, revealing triple anchoring mechanism at the Pt–CeO₂ interface: (1) Pt–O–Ce bond formation, (2) oxygen vacancies anchoring Pt atoms, and (3) charge redistribution stabilizing Pt oxidation states via strong metal–support interactions (SMSI). These effects collectively inhibit Pt sintering during hydrothermal aging, resulting in significantly higher Pt dispersion in aged Pt/CeO₂/Al₂O₃ (22.46 % vs. 3.33 %). Furthermore, the catalytic tests were conducted with the dual component catalytic system in which storage component BaCO 3 /BaAl 2 O 4 /γ-Al 2 O 3 was physically mixed with catalysts. It was found that fresh Pt/Al catalysts possessed higher NO oxidation capacity due to superior Pt dispersion, the introduction of CeO₂ significantly enhanced thermal stability and maintained NO x reduction efficiency after hydrothermal aging due to Pt–CeO₂ interface effect. These findings establish a structure–function framework that enables independent optimization of oxidation and reduction functionalities in NSR systems via targeted interface engineering.