Cobalt catalysts for Fischer-Tropsch synthesis: The effect of support, precipitant and pH value

Abstract In this report, Co-based catalysts supported on ZnO, Al 2 O 3 and ZrO 2 as well as the ZrO 2 derived from different precipitants and different pH values were prepared by co-precipitation method. Their catalytic Fischer–Tropsch synthesis (FTS) performance was investigated in a fixed-bed reactor. The results revealed that Co catalyst supported on ZrO 2 exhibited better FTS catalytic performance than that supported on ZnO or Al 2 O 3 . For the Co/ZrO 2 catalyst, different precipitants showed the following an activity order of NaOH > Na 2 CO 3  > NH 4 OH, and the best pH value is 13. The catalysts were characterized by N 2 adsorption–desorption, XRF, XRD, H 2 -TPR, H 2 -TPD and TEM. It was found that the main factor affecting the CO conversion of the catalyst was the amounts of low-temperature active adsorption sites. Moreover, the selectivity of C 5 + hydrocarbons had a positive relationship with the peak temperature of the weak hydrogen adsorption sites. The higher the peak temperature, the higher the C 5 + selectivity is.