J. Vangestel et al., COMO AL2O3 VERSUS NIMO/AL2O3 SULFIDE CATALYSTS - SENSITIVITY TO REACTION CONDITIONS FOR HDS AND HYDROGENATION/, Bulletin des Societes chimiques belges, 104(4-5), 1995, pp. 189-195
Two industrial hydrotreating catalysts, CoMo/Al2O3 and NiMo/Al2O3, wer
e compared with respect to their activity and selectivity in thiophene
hydrodesulphurisation and cyclohexene hydrogenation at 280 degrees C
and 4 MPa. Their difference in catalytic properties for HDS and hydrog
enation was found strongly depend ent on the experimental conditions.
Addition of small amounts of H2S to the feed inhibits the activity of
both catalysts, but at high H2S levels, the catalysts remain active. A
new type of site is proposed to operate at high H2S levels. The NiMo
catalyst was found far more active than the CoMo catalyst at low H2S p
ressure, while the two catalysts became equivalent at high H2S levels.