The formation of subsurface oxygen on Pt{110} (1×2) from molecular-beam-generated O2 Δg1

Abstract

Adsorption dynamics of CO 2 on Zn-ZnO(0001): A molecular beam study J. Chem. Phys. 122, 044705 (2005); 10.1063/1.1834490 CO-induced restructuring of Pt(110)-(1×2): Bridging the pressure gap with high-pressure scanning tunneling microscopy An unusually high-peak-temperature desorption state of O 2 from Pt͕110͖ (1ϫ2) has been characterized in temperature programmed desorption spectra after O 2 adsorption from a supersonic beam at a translational energy of 190 meV and at nozzle temperatures, T n , greater than 870 K. It shows the characteristics of a subsurface atomic state of oxygen. From the nozzle temperature dependence of the rate of population of this state we conclude that it is formed exclusively from electronically excited O 2 1 ⌬ g generated in the molecular beam source.

Formation of Molecularly Chemisorbed Oxygen on TiO2-Supported Gold Nanoclusters and Au(111) from Exposure to an Oxygen Plasma Jet

“…SDO has been observed to react in some metal complex systems forming metastable oxygenated compounds, which are not formed with ground-state oxygen . Walker and co-workers also suggested that SDO is responsible for the formation of subsurface oxygen on Pt{100}(1×2) during molecular beam exposures . This excited state of oxygen is known to be populated in plasma discharges, sometimes to a high degree, and it is likely present in our plasma jet also, as suggested by Pollard .…”

Formation and Thermal Stability of Platinum Oxides on Size-Selected Platinum Nanoparticles: Support Effects

“…The complete reduction of PtO 2 is observed above 750 K, while a small signal of Pt 2+ (∼13%) remains. The stronger stability of the PtO species on Pt/SiO 2 as compared to Pt/TiO 2 (Figure c) might indicate the existence of not just surface but also subsurface and/or interfacial Pt oxides. , The presence of subsurface oxygen on platinum was previously described by several other groups. − The possible enhanced stability of PtO x species at the Pt/SiO 2 interface still needs to be explored. However, such effect is unlikely to be dominant for the latter system due to the small contact area of our 3D NPs with the SiO 2 support, its low reducibility, and the fact that no drastic changes were observed in the decomposition pattern of the Pt/SiO 2 sample upon annealing in UHV [Figure a (closed symbols)] versus O 2 [Figure a (open symbols)].…”

“…93,133 The presence of subsurface oxygen on platinum was previously described by several other groups. [133][134][135][136][137] The possible enhanced stability of PtO x species at the Pt/SiO 2 interface still needs to be explored. However, such effect is unlikely to be dominant for the latter system due to the small contact area of our 3D NPs with the SiO 2 support, its low reducibility, and the fact that no drastic changes were observed in the decomposition pattern of the Pt/SiO 2 sample upon annealing in UHV [Figure 11a (111) and ZrO 2 (011) has been reported by Alfredsson et al, 139 and contrary to the previous study, no evidence for charge transfer at the Pt/ZrO 2 interface was found.…”

Colloidally Prepared Pt Nanowires versus Impregnated Pt Nanoparticles: Comparison of Adsorption and Reaction Properties

“…The absence of the pronounced CO peak around 2073 cm -1 clearly results from the oxidative pretreatment, which likely produced a PtO x surface oxide, [75][76][77][78][79][80] on which CO does not adsorb at 293 K (the weak 2115 cm -1 species may originate from CO-Pt nþ at the metal-support interface). Alternatively, a dense (compressed) layer of chemisorbed oxygen may prevent CO adsorption at 293 K. [81][82][83] In any case, CO exposure around room temperature did not reverse the effect of preoxidation; that is, CO reacted with neither PtO x 79 nor a dense oxygen adlayer (although it could account for the small metallic shoulder).…”