Effect of reduction temperature on the properties and Fischer-Tropsch synthesis performance of Fe-Mo catalysts

Effects of reduction temperature on the properties and Fischer-Tropsch synthesis (FTS) performance of Fe-Mo catalyst were studied. Catalysts were characterized by N₂ adsorption, X-ray diffraction (XRD), Mssbauer effect spectroscopy (MES) and H₂ temperature-programmed desorption (TPD). The characterization results indicate that the crystallite size of metallic iron, the reduction degree and the carbide content (in catalysts after reaction) monotonously increase with increasing reduction temperature, while the amount of H₂ chemisorption on metallic iron sites show a maximum at reduction temperature at 350 ℃. FTS performance was tested in a fixed-bed reactor at 280 ℃, 1.5 MPa, 2 000 h^-1 and syngas H₂/CO= 2.0. It is found that the steady-state FTS activity and the heavy hydrocarbons (C₅⁺) selectivity of the catalyst increase up to 350 ℃, and then decrease with further increasing reduction temperature. The catalyst redu at 350 ℃shows the optical FTS performance.