Effective E‐Gasoline Production via CO2‐Modified Fischer‐Tropsch Synthesis

This study explores multifunctional Na/Fe3O4–zeolite catalysts for the direct conversion of CO2 and H2 into e-gasoline via CO2-modified Fischer–Tropsch synthesis. A Na-promoted Fe3O4 catalyst was combined with MFI-type zeolites (H-ZSM-5) of different acidity to investigate how pretreatments, acidity and arrangement influence iron phase evolution, secondary upgrading, and deactivation. XRD and Mössbauer spectroscopy show that the iron phase distribution obtained during pretreatment is largely retained in the presence of zeolite, whereas under reaction conditions it favors a more oxidizing local environment consistent with H2O retention, promoting iron carbide oxidation and decarburization. In parallel, ASTM D6730 protocol was employed to characterize the oil fraction and estimate the fuel quality with respect to EN-228 targets. Catalytic tests identified zeolite with intermediate acidity (SiO2/Al2O3 = 80) and the smallest crystallite size (40–150 nm) as optimal: AC80 sample delivers the most favorable liquid composition, with the highest aromatic content and an estimated research octane number above 90. Moreover, NH3-TPD and TEM were used to quantify neutralization and alkali migration across the phases, that were limited by a dual-bed arrangement. Overall, these findings provide insights into the role of H2O diffusion, alkali migration, and iron phase evolution in steering product distribution toward gasoline range.