Robust Pt@TiO_x/TiO₂ Catalysts for Hydrocarbon Combustion: Effects of Pt-TiO_x Interaction and Sulfates

Developing platinum catalysts highly active for hydrocarbon combustion at low temperatures is crucial but yet challenging, since platinum may convert into inert PtO_x in oxidizing atmospheres and deactivates during catalytic combustion. In this article, a Pt@TiO_x/TiO₂ catalyst with platinum nanoparticles decorated by amorphous TiO_x overlayers was synthesized via a strong metal–support interaction (SMSI)-related strategy. The Pt-TiO_x electronic interaction stabilized reactive Pt⁰ sites during reactions, resulting in outstanding activities and high stability for C₃H₈ and C₃H₆ combustion. The influences of sulfatescommon byproducts forming on catalysts applied for automobile exhaust purificationwere studied by monitoring the platinum states, the hydrocarbon adsorption behavior, and the catalytic performance of sulfated Pt@TiO_x/TiO₂ with in situ DRIFTS. It is suggested that the sulfates promoted C₃H₈ combustion via heterolytic C–H bond activation on Pt^δ+–(SO₄)^δ− couples, while C₃H₆ combustion was disfavored on the sulfated catalyst because of inhibited O₂ activation.