عنوان مقاله [English]
The commercial hydrodesulfurization catalysts are composed of sulﬁdes of Mo as active component and Co (Ni) promoters supported on γ-alumina. The physical characteristic of the support (surface area, pore volume and pore diameter), interaction of active components-support and support acidity are the effective parameters on the catalytic activity. The support with large pore increases the life time and activity of the heavy oil catalyst. In the active phase of catalyst, the interaction of support and active component is low. The usage of chelating agents prevents the formation of inactive phase and increases the catalytic activity. Using additives such as phosphorous and boron can lead to improving the acidity of the catalysts and decreasing the interaction of active metals with supports which causes an increase in catalyst performance. In this review, the importance of hydrodesulfurization process, catalysis phases and the role of effective parameters on the catalyst activity are discussed.