Stability of MCM-41-Supported CoMo Hydrotreating Catalysts

The performance of sulfided CoMo hydrotreating catalysts supported on MCM-41 has been evaluated using hydrodesulfurization of 4-ethyl, 6-methyl- dibenzothiophene (4E,6M-DBT) model compound in n-hexadecane and of 4-methyl, 6-methyl-dibenzothiophene (4,6-DMDBT) in a commercial feed as a test reaction. Although the performance of CoMoS/MCM-41 is high for the model feed reaction as compared to commercial CoMoS/alumina, for the commercial feed reaction the performance of the commercial catalyst is much better. Model feed reaction with the addition of carbazole shows that, although this nitrogen-containing compound has a strong inhibiting effect, the lower catalytic performance of CoMoS/MCM-41 in the commercial feed test is probably not solely due to the presence of nitrogen.