Solution preparation of the amorphous molybdenum oxysulfide MoOS2 and its use for catalysis
Résumé
Acid condensation of aq. MoO2S2-2 anion yields amorphous MoOS2 oxysulfide. This compd. possesses tubular morphol. and when freshly pptd. is sol. in polar orgs. such as acetone and ethanol. The ensemble of characterizations (IR, UV-visible, EXAFS spectroscopy) suggests that it contains cyclic or short linear oligomers of neutral molybdenum (V) oxysulfide MoOS2 core. Thermal decompn. of MoOS2 under inert atm. leads to the formation of a mixt. of MoO2 and MoS2 phases. Promotion of MoOS2 with cobalt followed by sulfidation leads to highly active HDS catalysts.