The kinetics of the hydrodesulfurization(HDS) of dibenzothiophene(DBT) has been studied over a NiO-MoO₃/Υ-Al₂O₃ catalyst in the temperature range of 473-673 K for partial pressures of DBT from 20×10⁵Pa. A form of the Langmuir-Hinshelwood type rate equation was used to describe the kinetics of the reaction. The reaction was carried out at low conversion level to obtain initial reaction rate data. From this study the rate equation giving
the best fit to the data was r= ( K_DP_DP_H / [1+K_DP_D+(K_HP_H)^1/2]²) , which suggests that DBT and hydrogen adsorb on the same type of active sites and the hydrogen adsorbs dissociatively.