Study on iron-manganese catalysts for Fischer-Tropsch synthesis

Iron-manganese catalysts were prepared by co-precipitation method. Characterization of catalysts was carried out by using X-ray diffraction (XRD), scanning electron microscopy (SEM), temperature program reduction (TPR), N₂ adsorption-desorption measurements. The results from catalytic performance tests in Fischer-Tropsch synthesis showed that the iron-manganese catalysts are supersensitive to catalyst composition and materials source. It was found that C_2～4 light olefins increased while CH₄ and CO₂ decreased by using iron-manganese catalyst prepared from iron (Ⅱ) sulfate (A catalyst). The activity and selectivity of A catalyst was studied in different operational conditions. The results showed that the best operational conditions for C_2～4 light olefins production were H₂/CO=1/1 (GHSV=2 400 h^-1) at 260 ℃ under 0.3 MPa total pressure.