Magnesia supported Ni—Mo sulfide hydrodesulfurization and hydrodenitrogenation catalysts prepared by non-aqueous impregnation

• Published in: Applied catalysis. A, General General, 1994-10, Vol.118 (2), p.111-125
• Main Authors: HILLEROVA, E, VIT, Z, ZDRAZIL, M
• Format: Article
• Language: English
• Subjects: Catalysis; Catalysts: preparations and properties; Chemistry; Exact sciences and technology; General and physical chemistry; Hydrodenitrogenation; Hydrodesulfurization; Hydrotreating catalysts; Impregnation (non-aqueous); Nickel-molybdenum/magnesia; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 0926-860X; 1873-3875
• DOI: 10.1016/0926-860X(94)80307-2

Magnesia supported Ni—Mo sulfide catalysts were prepared by three methods: by impregnation from aqueous solutions, by precipitation-adsorption of Sulfides in a water-toluene emulsion, and by impregnation from non-aqueous solutions using dimethylsulfoxide and methanol as solvents. They were tested in: (i) the single hydrodesulfurization of thiophene (HDS), and (ii) the parallel hydro-desulfurization of thiophene (HDS,PY) and the hydrodenitrogenation of pyridine (HDN). The reference Ni-Mo / alumina catalyst was the commercial sample Shell 324. The catalytic activity of samples prepared by aqueous impregnation and by precipitation-adsorption was low, activity for (HDS) and (HDN) of the best sample being only about 30 and 20%, respectively, of the activity of the Shell 324 catalyst at 320°C. The chemical and textural instability of the high surface area magnesia in aqueous solutions was the limiting factor. Much higher activity was achieved by non-aqueous impregnation, activity of the best Ni-Mo/MgO sample prepared by this method for (HDS), (HDS,PY) and (HDN) being 94,290 and 105%, respectively, of the activity of the Shell 324 catalyst at 320°C. As compared with the alumina supported catalyst, the special feature of the Ni-Mo/MgO catalysts irrespective of the preparation method was lower inhibition of HDS by parallel HDN and lower selectivity to HDN in parallel HDN and HDS.