Mechanism of Non-Contact Reduction of MoO3 to Prepare MoO2

In this present study, carbothermic reduction process of MoO 3 to produce MoO 2 has been carried to investigate the influences of reaction temperature and distance between activated carbon and MoO 3 on phase composition of reduction products by controlling carbon diffusion. Results show that the reduction degree increases with the increase of temperature and the decrease of distance between activated carbon and MoO 3 . MoO 3 can be completely reduced to MoO 2 at 680°C with the carbon distance of 1 mm. It is found that the transformation from MoO 3 to MoO 2 is a process of crystal cracking and growth by observing the phase transition and morphological evolution during the reduction. The massive MoO 3 is first decomposed into a platelet-shaped MoO x (2.75 < x < 3), then the platelet-shaped MoO x changes into a needle-like shape or irregular platelet-like Mo 4 O 11 , and finally Mo 4 O 11 changes into irregular granular or irregular platelet-like shaped crystals, which form MoO 2 powders.