Robust Pt@TiOx/TiO2 Catalysts for Hydrocarbon Combustion: Effects of Pt-TiOx 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 PtOx in oxidizing atmospheres and deactivates during catalytic combustion. In this article, a Pt@TiOx/TiO2 catalyst with platinum nanoparticles decorated by amorphous TiOx overlayers was synthesized via a strong metal-support interaction (SMSI)-related strategy. The Pt-TiOx electronic interaction stabilized reactive Pt-0 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@TiOx/TiO2 with in situ DRIFTS. It is suggested that the sulfates promoted C3H8 combustion via heterolytic C-H bond activation on Pt delta+-(SO4)(delta-) couples, while C3H6 combustion was disfavored on the sulfated catalyst because of inhibited O-2 activation.