CO and O2 adsorption on the Re/Pt(111) surface studied by photoemission and thermal desorption.

XPS study of oxidation of rhenium metal on ?-Al2O3 support

“…The conclusion was based on the observed shift of 1.1 eV in the Re 4f XPS signal upon oxygen dosage. Similar Re 4f line shifts was observed more recently by Ramstad et al [35] for the oxidation of thin Re islands on Pt(111). Very recently, Liu and Shuh [36] showed for polycrystalline rhenium, that such small changes in the Re 4f binding energy may be assigned with both molecular and dissociative adsorption of oxygen and that there is little, if any, Re oxide formed on the surface.…”

“…A large chemical shift of about 7 eV occurs between the Re metal and the highest rhenium oxide, Re 2 O 7 ; therefore, rhenium is particularly amenable to this method of analysis. Rhenium-oxygen interactions were studied by XPS mainly in simple systems such as thin films [28,35], foils and ribbons [36], and single crystals [37]. For supported rhenium catalysts, XPS was used to examine the oxidation states of rhenium after reduction [38][39][40] or more often after oxidation at high temperature [41][42][43][44][45][46].…”

Extra electronic outer-shell peculiarities accessible under a joint XPS and DFT study

“…1 particularly exhibit 1p, 5s, and 4s valence states of the adsorbed CO molecule and the s state of H ad species, which fit published UPS data. [32][33][34][35] Similar accordance has been found for adsorbed O, N, NO, and NH particles. The theoretical Pt shake-off spectrum in Fig.…”

Characterization of Pt–Au and Ni–Au Clusters on TiO2(110)

“…The Pt(4f 7/2 ) binding energy shifts from 71.5 eV for the unannealed clusters to 71.6 and 71.7 eV after heating to 700 and 800 K, respectively. The shift to higher binding energy is explained by a reduced contribution from surface Pt atoms as the Pt clusters become encapsulated [29], given that a 0.4-0.5 eV splitting between bulk and surface states has been reported on Pt(111) [45][46][47][48][49]. Binding Energy (eV) For the 2 ML Pt ?…”