| abstract |
A cobalt-molybdenum catalyst and a method for preparing same, said catalyst useful for the hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) of distillates of petroleum. The catalyst is supported by aluminum phosphate or an aluminum borate. In a preferred embodiment the catalyst has a low cobalt content, between 0.5% and 2.0% by weight calculated as CoO, and a molybdenum content of between 10% and 20% by weight, calculated as MoO3. The phosphorus or boron compounds added to the aluminum before the impregnation of the active metals prevents the formation of undesirable compounds of the CoAl2O4 type, which is inactive in HDS. It is for that reason that the catalyst has a formulation with 70% less cobalt than the previous state-of-the-art catalysts. Very small crystals, highly dispersed on the surface of the catalyst, whose formula is CoMoO4, are responsible for the stability and the high level of activity in HDS and HDN which results. |