Improved CO conversion and light olefins selectivity in Fischer–Tropsch synthesis: a study of Fe/γ-Al2O3 catalysts with Mn, Zn, and Mo promoters

This research examines the effects of adding promoters (Mn, Zn, Mo) to γ-Al2O3 supports, along with Fe as the active metal, on catalyst performance in Fischer-Tropsch synthesis for generating light olefins from synthesis gas. The catalysts were created through the dry impregnation method. Post-production, the catalysts were evaluated for CO conversion rates and selectivity towards light olefins in a reactor system, alongside analyses of their physical and chemical properties using techniques like XRD, BET, H2-TPR, ICP, and FESEM. Introducing these promoters modified aspects such as surface area, pore size, metal dispersion, and catalyst regeneration capabilities. Temperature increases from 300°C to 360°C led to higher CO conversion rates, improved selectivity for light olefins, and greater methane production. The inclusion of Mn and Zn promoters not only enhanced light olefin production and CO conversion rates but also lowered methane formation, an unwanted byproduct. Moreover, the Mo promoter markedly improved the catalysts’ effectiveness and selectivity for light olefins. The most effective catalyst was identified as cat5 (10% Fe-3% Mn-1.5% Zn-1.5% Mo-γ-Al2O3). This catalyst showed 86.66% CO conversion, 40.4% selectivity for light olefins and 35.01% efficiency.