Spatially and Electronically Co-Confinement Effect on Pt/TiO2@SiO2 for Durable Propane Oxidation

Abstract

Inherent instability of highly active metal nanoclusters limits their practical application in thermal catalysis. Core–shell architectures, while improving stability, commonly sacrifice low-temperature activity by blocking essential active sites, particularly in interface-mediated reactions. To overcome this activity–stability trade-off, we constructed a “well-like” Pt/TiO2@SiO2 catalyst in which PtO species are anchored on defect-rich TiOx and confined within a porous SiO2 shell. In propane oxidation, the resulting catalyst achieves a T90 of 199 °C, 102 °C lower than that of conventional Pt/TiO2, and exhibits approximately 16-fold higher activity at 200 °C, while showing negligible deactivation over 36 h of continuous operation and retaining a T90 of 254 °C after severe hydrothermal aging. Characterization and simulations reveal that the initially inactive PtO species undergo in situ reduction to form partially reduced PtOx nanoparticles of approximately 3.7 nm. Coordinatively unsaturated metallic Pt sites on these nanoparticles promote propane adsorption and C–H bond cleavage. Electron donation from defect-rich TiOx stabilizes this active electronic state, while the porous SiO2 shell suppresses Pt agglomeration and TiO2 coarsening. This work establishes a rational design strategy for advanced catalysts that combine high activity at low temperatures with long-term durability.