Influences of Al2O3 on the structure and reactive performance of Co/ZnO catalyst

Cobalt-based catalysts supported on ZnO and Al2O3 were prepared by sequential precipitation method. With the increase of Al2O3 content, BET surface area of the catalysts is increased, while the reducibility of cobalt species decreased correspondingly. These indicate that Al2O3 acts as a structural promoter to Co/ZnO catalyst and the interaction between Co and Al2O3 is stronger than that between Co and ZnO. CH4 selectivity for Fischer-Tropsch synthesis was raised with the addition of Al2O3 to Co/ZnO catalyst. Catalyst with 2 wt.% of Al2O3 exhibits the best performance among the studied catalysts in view of catalytic activity, selectivity and stability.

► ZnO is a support seldom studied in cobalt based catalysts for Fischer-Tropsch synthesis.
► The surface area of ZnO is smaller than that of Al2O3, SiO2 and TiO2.
► The FTS activity of Co/ZnO is high.
► Adding Al2O3 can increase the surface area of catalyst and stabilise the catalyst.
► Co/ZnO–2Al2O3 exhibits the best reaction performance among the studied catalysts.