Solid state reaction of MoO_3-CeO_2 complex oxide studied by Raman spectroscopy

摘要

The effects of MoO_3 content and calcination temperature on the solid-state reaction of MoO_3-CeO_2 complex oxide were studied by Raman spectroscopy and XRD. Depending on the MoO_3 content, molybdenum oxide species were found to exist as the highly dispersed molybdate, crystalline Ce_8Mo_(12)O_(49) and Ce_2Mo_4O_(15) for the MoO_3-CeO_2 complex oxide calcined at 500 °C resulting from the solid-state reaction between MoO_3 and CeO_2- Such a solid-state reaction is promoted at higher temperature. However, Ce_2Mo_3O_(13) is observed for 20% MoO_3-CeO_2 sample under O_2 atmosphere, which indicates Ce_2Mo_3O_(13) is formed firstly and then it is transformed into Ce_8Mo_(12)O_(49) at higher temperature during the solid-state reaction.