Characterization and HDS activities of mixed Fe–Mo sulphides supported on alumina and carbon

Alumina and activated carbon-supported mixed sulphides (FeMoS) were prepared as hydrotreating catalysts. Previous work had shown bulk Fe–Mo mixed sulphides to be promising catalysts for hydrotreatment. Characterizations of the solids by NH3-TPD proved to be a good technique to classify the solids according to their acidic strength. Thiophene hydrodesulphurization (HDS) and High vacuum gas oil (HVGO) hydrotreatment, performed at atmospheric pressure and high pressure respectively, were used as catalytic tests. Depending on the support, a more or less important synergetic effect is observed. The results are in agreement with a possible direct desulphurization process. The acidic strength plays an important role in determining the hydrogenolysis/hydrogenation ratio of the catalysts.