Infrared and Raman study of WO3 tungsten trioxides and WO3, xH2O tungsten trioxide tydrates

Raman and IR studies of surface metal oxide species on oxide supports: Supported metal oxide catalysts

Infrared and raman spectra of moo3 molybdenum trioxides and moo3.xh2o molybdenum trioxide hydrates

The sulfidation of crystalline MoO3 and the thermal decomposition of (NH4)2MoO2S2 to MoS2 via an {MoOS2} oxysulfide intermediate have been studied by means of monochromatic X-ray photoelectron spectroscopy (XPS) and infrared emission spectroscopy (IRES) Several basic steps of the sulfidation reaction could be resolved and explained in terms of the structure of crystalline MoO3 The sulfidation reaction starts at low temperatures with an exchange of terminal O2- ligands of the oxide for S2- by reaction with H2S from the sulfiding atmosphere In subsequent Mo−S redox reactions, bridging S22- ligands and Mo5+ centers are formed Lattice relaxation and further sulfur uptake are the main processes before, at temperatures above 200 °C, direct reactions with H2 occur, during which the Mo5+ centers are converted into the 4+ oxidation state The decomposition experiments with (NH4)2MoO2S2 show that terminal O2- ligands serve as the reactive sites The conversion of terminal MoOt to MoS entities and the subsequent

/pdf/basic-reaction-steps-in-the-sulfidation-of-crystalline-moo3-ub1x9ubuyz.pdf

F. A. Cotton

Papers

Properties of Metal-to-Oxygen Multiple Bonds, Especially Molybdenum-to-Oxygen Bonds