The characterization of the micro-structure of cobalt on gamma-Al2O3 for FTS

Abstract

Ruthenium promoted cobalt supported on gamma-Al2O3 catalysts were prepared by different slurry impregnation method and calcined at hydrogen/air atmosphere. The prepared catalysts were well characterized by N-2 physisorption, TPR, XRD, TEM and XPS techniques. The addition of Ru caused the reduction peaks shift towards lower temperatures, due to spillover of hydrogen from Ru species. The ruthenium promoted catalalyst calcined under hydrogen atmosphere leads to the metallic cobalt of hcp structure and shows the good catalytic activity for Fischer Tropsch synthesis under the reaction condition studied. The catalyst calcined under air atmosphere leads to the metallic cobalt with fcc structures and showed lower catalytic activity. It was also found that calcination atmosphere and structure of the catalyst have profound effect on the activity and selectivity for FT synthesis.