XPS study of MoO₂, WO₂ and WO₃ and their catalytic activities in the izomerization reactions of alkanes

X-ray photoemission study ofSr2FeMoO6andSrMoO4films e

“…36͒ and a 3d 5/2 :3d 3/2 intensity ratio of 3:2 have been used for the fitting after appropriate correction of the background with a single Shirley ͑Gaussian-step͒ function. Using the literature values for different Mo oxides, 23,34,36 we assign the observed Mo 3d 5/2 ͑3d 3/2 ͒ features at 228.5 eV ͑231.6 eV͒, 230.8 eV ͑233.9 eV͒, 232.2 eV ͑235.3 eV͒, and 233.7 eV ͑236.7 eV͒ to Mo 0 ͑i.e., metallic Mo͒, Mo 4+ , Mo 5+ , and Mo 6+ states, respectively. An excellent fit has been obtained when the peak widths for the Mo 0 , Mo 4+ , Mo 5+ , and Mo 6+ features were set to 1.0Ϯ 0.2 eV, 2.4Ϯ 0.2 eV, 1.2Ϯ 0.2 eV, and 1.3Ϯ 0.2 eV FWHM, respectively.…”

MoxCu1−xSr2YCu2Oy (0.3≤x≤1) revisited: Superconductivity, magnetism and the molybdenum oxidation state

“…We have observed a peak broadening for the oxygen annealed sample compared to the as-prepared sample. A spin-orbit splitting of 3.1 eV [18] and a 3d 5/2 :3d 3/2 intensity ratio of 3:2 have been used for the fitting after appropriate correction of the background with a single Shirley (Gaussian-step) function ( Table 3). Fitting of the XPS spectra of Mo 3d core levels allows us to confirm the large content of Mo 5 þ .…”

A new route to the metastable FCC molybdenum carbide α-MoC1−x

“…10 The oxyhydride has an FCC structure with a cub = 0.410 nm and is formed by reduction and hydrogen insertion in the MoO 3 lattice, the overall process being topotactic. 11 Dihydrogen was then replaced by methane and the sample (mixture of MoO 2 and MoO x H y ) heated progressively to 710 °C (3 °C min 21 ). In situ fast scan XRD analyses were performed at regular 30 °C temperature intervals to follow the carburisation of the sample.…”