Effects of impregnation solvent on Co/SiO₂ catalyst for Fischer-Tropsch synthesis: A highly active and stable catalyst with bimodal sized cobalt particles

Silica-supported cobalt (20 wt%) catalysts were prepared by incipient-wetness impregnation of silica with different cobalt nitrate solutions. The catalyst prepared from dehydration ethanol solution exhibited stable and the highest activity, as well as significantly low methane selectivity. Cobalt crystalline size of the catalyst prepared from dehydrated ethanol was smaller than that of the catalyst prepared from aqueous solution, and existed two different size where the large particles showed low bulk density with cluster-like structure. But only larger clusters existed in the catalyst prepared from aqueous solution. The increased amount of active sites and more reactive adsorbed CO on the surface determined the highest activity of the catalyst prepared from dehydrated ethanol solution in liquid-phase Fischer-Tropsch synthesis (FTS) reaction.