Interfacial charge transfer in Pt-loaded TiO2 P25 photocatalysts studied by in-situ diffuse reflectance FTIR spectroscopy of adsorbed CO

A readily available and efficient Pt/P25 (TiO2) catalyst for glycerol selective oxidation

“…The former is attributed to the linearly absorbed CO on Pt 0 sites (LCO), and the latter is corresponding to bridging CO on Pt terraces sites (BCO). Notably, the LCO adsorption mode is the dominant one in both catalysts, while the LCO band of Pt/ P25 shifts to lower wavenumber (12 cm −1 ) compared with Pt/(A + R), implying the electron‐rich state of Pt in Pt/P25 30 …”

“…Notably, the L CO adsorption mode is the dominant one in both catalysts, while the L CO band of Pt/ P25 shifts to lower wavenumber (12 cm À1 ) compared with Pt/(A + R), implying the electron-rich state of Pt in Pt/P25. 30 Furthermore, the XPS analysis is used to reveal the electronic structure of Pt and Ti species. 31,32 Figure 4B shows that the Pt 4f XPS spectrum can be fitted into two primary peaks attributed to Pt 0 4f 5/2 and 4f 7/2 , two small shoulders associated with Pt 2+ 4f 5/2 as well as As reported, the oxygen activation needs the participation of metal component.…”

Autocatalysis through the Generation of Water during Methanol Oxidation over a Titania-Supported Platinum Catalyst

“…The charged methoxonium was suggested to then further react to yield H 2 O and a reduced metal site, while the remaining methyl group was suggested to combine with a nearby methanol to form dimethyl ether. Another previously described channel for water formation involves the protonation of surface free hydroxyl groups to yield H 2 O upon the initial dissociative adsorption of methanol. ,, …”

“…In the absence of oxygen, methanol adsorbs both molecularly and dissociatively onto both of the TiO 2 and Pt/TiO 2 surfaces. The infrared bands at 2925 and 2825 cm –1 are attributed to the asymmetric and symmetric C–H stretches of surface-bound Ti–OCH 3 species. ,, In addition, the bands located within the C–O stretching region of the infrared spectrum at 1129 and 1051 cm –1 are indicative of methoxy species bound to the titania support. , On the Pt/TiO 2 sample, a feature assigned to CO on Pt 0 is present at 2045 cm –1 . − Remarkably, the carbon monoxide product (which requires the full dehydrogenation of methanol) was readily formed over the Pt nanoparticles in the absence of oxygen at low temperatures. In addition to the carbon-containing species, noticeable infrared features attributed to water formation were evidenced on the Pt-containing sample.…”

Photocatalytic Hydrogen Production Using Porous 3D Graphene-Based Aerogels Supporting Pt/TiO2 Nanoparticles

“…The oxygenated functionalities facilitate the dispersion and exfoliation of GO in aqueous and polar solutions via simple sonication. Moreover, preserving the oxygenated functional groups in GO during scCO 2 aerogel synthesis was essential to ensure the presence of many anchoring points on the substrate for the NPs, which guarantees the establishment of strong interactions with a net or composed hydrophilic TiO 2 involving hydroxyl groups on the surface [ 32 , 38 , 39 ]. Three different compositions for the NPs in the intermediate were tested, namely, 1Pt/TiO 2 @GO, 0.5Pt/TiO 2 @GO, and 0.1Pt/TiO 2 @GO, corresponding to an initially mixed amount of Pt with the TiO 2 NPs of 1, 0.5 and 0.1 wt%, respectively.…”