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

In this report, Co-based catalysts supported on ZnO, Al2O3 and ZrO(2 )as well as the ZrO2 derived from different precipitants and different pH values were prepared by co-precipitation method. Their catalytic Fischer-Tropsch synthesis (PIS) performance was investigated in a fixed-bed reactor. The results revealed that Co catalyst supported on ZrO2 exhibited better FES catalytic performance than that supported on ZnO or Al2O3. For the Co/ZrO2 catalyst. different precipitants showed the following an activity order of NaOH > Na2CO3 > NH4OH, 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. (C) 2017 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.