Preparation of MoO2 by the Solid State Reaction Between MoS2 and MoO3

In the present study, the solid state reactions between molybdenum disulfide (MoS2) and molybdenum trioxide (MoO3) under different mixing molar ratios and different reaction temperatures have been investigated in order to produce industrial grade molybdenum dioxide (MoO2). It was found that it was difficult to react completely when the temperature was less than 873 K. However, when the temperature was up to 923 K or 973 K, the final product MoO2 with low residual sulfur can be obtained. Results of the residual sulfur levels at different conditions show that the content of residual sulfur decreases with the increase of temperature. In addition, the excess additions of MoO3 are effective and necessary in order to decrease the residual sulfur level. When the mixing molar ratio of MoS2 to MoO3 is 1:6.5, the content of residual sulfur can decrease down to 0.075% at 973 K. It was also found that the reaction between MoS2 and MoO3 obeyed the shrinking core model.