Abstract: Fischer-Tropsch synthesis (FTS) is one of the main industrial routes for the preparation of α-olefins, but it is plagued by low α-olefin selectivity, severe methane side reactions and insufficient catalyst stability. This study aims to prepare Fe-xBa and Fe-yZr catalysts with different Ba or Zr loading by co-precipitation and equal volume impregnation methods, and explore their effects on the performance of FTS for α-olefin production. The physicochemical properties of the catalysts were characterized by XRF,XRD,TEM,etc. The experimental results show that the introduction of Ba enhances the density of surface basic sites and the electron transfer effect, significantly improving the CO dissociative adsorption capacity and inhibiting the methane side reaction, resulting in an α-olefin content (mass fraction) of 48.17% in the liquid product of the catalyst. The Zr additive optimizes the pore structure and promotes the dispersion of Fe particles, enhancing the catalytic stability. The catalyst achieved a CO conversion rate of 78.98% and an α-olefin selectivity of 48.63% in a 48-hour reaction, while the selectivities of CO₂ and CH₄ were reduced to 37.73% and 6.54%, respectively. Appropriate Ba/Zr modified iron-based catalysts can both enhance the α-olefin selectivity and suppress the selectivities of CH₄ and CO₂.

Key words: Fischer-Tropsch synthesis, iron-based catalyst, α-olefins