Effect of High Pressure Sulfidation on the Structure of Sulfide Sites of Hydrotreatment Catalysts

International audienceThe effect of high-pressure sulfidation on (Co)Mo/Al(2)O(3) catalysts was studied by means of IR spectroscopy of adsorbed CO and thiophene hydrodesulfurization (HDS). A new IR cell, called CellEx, was designed in order to characterize catalysts sulfided in situ under H(2)S/H(2) flow with pressure varying from 0.1 up to 4.0 MPa. On Mo/Al(2)O(3), high sulfidation pressure changes neither the HDS rate nor the MoS(2) site concentration. Conversely on CoMo catalyst, sulfidation under high pressure leads to a marked increase of the thiophene HDS activity and of the Co-promoted site concentration as well as to some changes in the local structure of CoMoS sites