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

Abstract

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 Ptδ+–(SO4)δ− couples, while C3H6 combustion was disfavored on the sulfated catalyst because of inhibited O2 activation.

Chemoselective NADH Regeneration: the Synergy Effect of TiOx and Pt in NAD+ Hydrogenation

“…45 The signal intensity of V O for Pt/ana-450 and Pt/ana-550 decreased, which could be associated with the reduction of surface areas and the partial phase transformation of anatase to rutile. It should be noted that Pt/ana-450 and Pt/ana-550 showed signals at a g value of 1.997, 1.972, and 1.934, ascribed to Ti 3+ species, 46,47 which could be derived from the TiO x overlayer encapsulated on Pt. The abovementioned results clearly demonstrated the formation of the SMSI effect after the high temperature reduction treatment of Pt/TiO 2 .…”

Surface‐Confined Synthesis of Ultrafine Pt‐Rare Earth Nanoalloys on N‐Functionalized Supports

“…The ultrafine particle size and excellent thermal withstanding capacity (control experiments show that the 2.8±0.7 nm Pt 6 La only slightly increases to 3.4 ± 1.2 nm after 850 °C H 2 annealing for 2 h and 3.0 ± 0.9 nm after 850 °C Ar annealing for 2 h as displayed in Figure S25, Supporting Information) endow these Pt-rare earth nanoalloys with great potential for practical applications. For example, the PtLa/NHY with PtLa NPs size of 2.1 ± 0.5 nm exhibited excellent catalytic properties toward propane oxidation (Figure 6), [28][29][30][31][32][33] a crucial reaction in eliminating air pollutants that derived from automotive exhaust, liquefied petroleum gas, etc. [25] The PtLa/NHY displays a full propane conversion temperature as low as 280 °C at a gas flow rate (GHSV) of 36 000 mL h −1 g −1 and 300 °C at a GHSV of 240 000 mL h −1 g −1 as displayed by the light-off curves in Figure S26 (Supporting Information).…”

Engineering the geometric and electronic structure of Ru via Ru–TiO2 interaction for enhanced selective hydrogenation

“…During the high temperature reduction process of TiO 2 supported catalysts, the geometric structure of the active metals changed significantly due to the coating of active metals by TiO 2 . [27][28][29] Meanwhile, the high temperature reduction process will produce oxygen vacancies, which are one of the most important defects of TiO 2 . 26,30 It is worth noting that the effect of oxygen vacancies on the catalytic reaction and diffusion is not studied in detail.…”

“…[27][28][29] Meanwhile, the high temperature reduction process will produce oxygen vacancies, which are one of the most important defects of TiO 2 . 26,30 It is worth noting that the effect of oxygen vacancies on the catalytic reaction and diffusion is not studied in detail. In fact, the generation of vacancies will not only significantly modulate the electronic structure of the active metal, but also provide supplementary active sites to adsorb substrate molecules.…”