Exploring the influence of zeolite textural properties on the production of sustainable fuels through the Fischer-Tropsch process

The isolated impact of the textural properties of hierarchical zeolites on the one-step Fischer-Tropsch (FT) reaction selectivity was studied. Hierarchical ZSM-5 zeolites with different pore size distributions (PSD) and similar acid properties were successfully prepared evidenced by PXRD, ²⁷Al MAS NMR, N2 physisorption, TEM, TPD NH₃ and FTIV. Physical mixtures comprising the zeolites, Co/Al₂O₃ and Pt/Al₂O₃ were used for testing. The Mixtures containing Pt/Al₂O₃ evidenced a decrease on the olefin content of the final products. The addition of zeolite to the mixture increased the CH₄ and C_2–4 selectivity and a decrease in CO₂ selectivity. The hierarchical zeolites increased the selectivity towards liquid products and isomers while decreasing the consecutive cracking. The highest isomer content was obtained with the physical mixture containing the hierarchical zeolite with higher mesopore average size (60 nm) and narrow PSD, suggesting a correlation between the PSD and the isomer content of the final products.