New shearing mechanical coating technology for synthesis of alumina supported cobalt Fischer-Tropsch solid catalysts
This work presents a novel dry coating technology for Co/Al2O3 catalysts synthesis without solvents and heating treatment. Nano crystallized Co3O4 powders were mechanically coated onto γ-Al2O3 using advanced high-shear batch mixer “Picomix”. The interaction between support and Co3O4 was produced by shearing force of that the blades in the jar and van der Waal adhesion force. The uniform coating layer with 1 µm to 3 μm thickness has been observed. Co3O4 diffusion into γ-Al2O3 pores has not occurred, which results in “egg-shell” structure formation. Undesirable cobalt aluminate compounds which are difficult to reduce and inactive in Fischer-Tropsch synthesis have not been generated. The dry coated catalysts exhibited catalytic performance in Fischer-Tropsch synthesis comparable to the catalysts prepared by conventional chemical impregnation.