Sulfurization and reduction of V2O3-MoO2 catalyst have been studied kinetically.V2O3 is not sulfurized with H2S at lower temperature than 480°C, but MoO2is sulfurized to MoS2+x (x=0.3) with CS2, H2S, and thiophene in the temperature range 400∼480°C.The reduction of MoS2+x with H2 is difficult at 400°C, but it proceeds slowly to MoS1.86at 600°C.
Sulfurization rate of this MoS1.86were measured.The kinetic orders of sulfurization were1.2th, 0.5th and 0.9th for CS2, H2S and thiophen respectively, and the reactivities of these compounds decreased in the preceding order.
The catalyst of molar ratio V2O3/MoO2=6was sulfurized most easily, so it was understood that the sulfurization process was the main step in the mechanism of hydrodesulfurization, for the desulfurization activity per unit area of catalyst was maximum at this composition as shown in the preceding paper.
Further, from the results of electric conductivity measurements of the catalyst, it was supposed that the catalysis displayed activity under the co-operation betweenV2O3 (n-type semiconductor) and MoS2-x (p-type semiconductor).