Fischer-Tropsch synthesis. Effect of CO pretreatment on a ruthenium promoted Co/TiO2

The effect of pretreatment, using hydrogen or carbon monoxide, on the activ ity and selectivity of a ruthenium promoted cobalt catalyst (Ru(0.20 wt%)/C o(10 wt%)TiO2) during Fischer-Tropsch (FT) synthesis was studied in a conti nuous-stirred tank reactor (CSTR). The hydrogen reduced catalyst exhibited a high initial synthesis gas conversion (72.5%) and reached steady stale af ter 40 h on stream, after which the catalyst deactivated slightly with time on stream. The carbon monoxide reduced catalyst reached steady state quick ly and showed a lower activity and a good stability. Methane selectivity on the carbon monoxide reduced catalyst was 15-20% (carbon base), much higher than that on the hydrogen reduced catalyst (5-10%). Carbon monoxide regene ration increased the activity on the hydrogen reduced catalyst; however, it did not have significant effect on the carbon monoxide reduced catalyst.