The effects of oxidation–reduction treatment on the structure and activity of cobalt-based catalysts

Abstract This study reports the effects of oxidative-reductive (OR) treatment on 10 wt% Co/Al 2 O 3 and 0.25 wt% Ru-10 wt% Co/Al 2 O 3 catalysts. Temperature-programmed analysis revealed that the cobalt in both catalysts became more reducible with increase number of OR treatment. A reduction–oxidation–reduction treatment increased Co surface area and dispersion of the Ru-Co/Al 2 O 3 catalyst from 7.6 to 10.1 m 2 /g and from 14.9% to 17.3%, respectively. The treatment also increased the CO conversion from 21% to 36% and accompanied a small increase in CH 4 selectivity in Fischer–Tropsch synthesis experiments. However, the effect of OR treatment on the Co/Al 2 O 3 catalysts was insignificant.