Cascade electron donation across Sn-Pt-TiO2 interfaces mobilizes lattice oxygen for low-temperature benzene combustion.

Catalytic combustion of benzene demands efficient low-temperature oxygen activation, yet mechanistic principles at bimetallic interfaces remain unclear. Existing Sn-Pt-TiO2 studies focused on CO oxidation, leaving multi-electron aromatic mineralization unaddressed. Here, we design Pt-SnOx/TiO2 catalysts to demonstrate a cascade interfacial electron-transfer: SnOx donates electrons to Pt, which subsequently mobilizes TiO2 lattice oxygen (O*). Comprehensive characterization reveals this two-step relay raises the metallic Pt⁰ fraction from 62.1% to 70.5%, generates unique surface peroxide/superoxide species, and delivers ∼198% more low-temperature reducible oxygen. Kinetic analyses confirm the electron-enriched Pt-SnOx interface achieves surface O* saturation at a lower O2 partial pressure than Pt/TiO2, providing direct kinetic evidence for augmented intrinsic O2 activation. Consequently, T90 decreases from 228 to 188 °C and the apparent activation energy drops from 128.3 to 99.6 kJ·mol-1, with accelerated phenolate formation and suppressed oxalate accumulation confirmed by in situ DRIFTS. Crucially, the negligible activity of Pt/SnO2 under identical conditions rules out SnOx as the primary oxygen source, confirming that the promoter functions predominantly as an electronic relay that mobilizes support lattice oxygen. This work establishes a transferable cascade design principle for engineering noble-metal/oxide interfaces in deep aromatic VOC oxidation.