Interface engineering of Pt/CeO2-{100} catalysts for enhancing catalytic activity in auto-exhaust carbon particles oxidation

Abstract

Herein, we fabricate an embedding structure at the interface between Pt nanoparticles (NPs) and CeO₂-{100} nanocubes with surface defect sites (CeO₂-SDS) through quenching and gas bubbling-assisted membrane reduction methods. The in-situ substitution of Pt NPs for atomic-layer Ce lattice significantly increases the amount of reactive oxygen species from 133.68 µmol/g to 199.44 µmol/g. As a result, the distinctive geometric structure of Pt/CeO₂-SDS catalyst substantially improves the catalytic activity and stability for soot oxidation compared with the catalyst with no quenching process, i.e., its T₅₀ and TOF values are 332 °C and 2.915 h^-1, respectively. Combined with the results of experimental investigations and density functional theory calculations, it is unveiled that the unique embedding structure of Pt/CeO₂-SDS catalyst can facilitate significantly electron transfer from Pt to the CeO₂-{100} support, and induce the formation of interfacial [Ce-O_x-Pt₂] bond chains, which plays a crucial role in enhancing the key step of soot oxidation through the dual activation of surface lattice oxygen and molecular O₂. Such a fundamental revelation of the interfacial electronic transmission and corresponding modification strategy contributes a novel opportunity to develop high-efficient and stable noble metal catalysts at the atomic level.