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

In this report,Co-based catalysts supported on ZnO,Al_2O_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_2O_3.For the Co/ZrO_2catalyst,different precipitants showed the following an activity order of NaOHNa_2CO_3NH_4OH,and the best pH value is 13.The catalysts were characterized by N_2adsorption–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.

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 ZrO2 as well as the ZrO2 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 ZrO2 exhibited better FTS 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 N2 adsorption-desorption,XRF,XRD,H2-TPR,H2-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 C5+ hydrocarbons had a positive relationship with the peak temperature of the weak hydrogen adsorption sites.The higher the peak temperature,the higher the C5+ selectivity is.