Steering 1-hexene oligomerization toward sustainable aviation fuel: Modulating acid sites in self-pillared nano-ZSM-5

Self-pillared nano-ZSM-5 (SPZ) boosts 1-hexene oligomerization stability for SAF. • Accessible strong Brønsted acid sites promote branching and cyclization reactions. • 2D-GC–MS shows C12–C17 products dominate while aromatization remains minor. • Lower N 2 flow favors deeper oligomerization, enriching heavier and jet-fuel-range products. • Oligomer-derived soft coke drives deactivation and enables partial N 2 reactivation. Developing high-performance catalysts for the oligomerization of bio-derived olefins into sustainable aviation fuels (SAF) is of paramount importance. However, simultaneously achieving high catalytic activity and selectivity while mitigating the rapid deactivation of nano-zeolites remains a formidable challenge. To drive the efficient production of SAF, a novel self-pillared nano-ZSM-5 (SPZ) zeolite featuring an enriched acidic profile was designed in this work, delivering exceptional activity, selectivity, and stability for 1-hexene oligomerization. Compared with nano-sized ZSM-5 featuring intercrystalline mesoporous voids (NSZ), the SPZ catalyst significantly improved catalytic performance, increasing 1-hexene conversion from 20% to 61% at 240 °C while prolonging catalyst lifetime. DTBPy-FTIR, and TEOS passivation collectively support the involvement of external and pore-mouth acid sites in 1-hexene conversion and further indicate that these accessible sites may also promote secondary cracking. Semi-quantitative, area-normalized 2D-GC–MS responses were dominated by C12-C17 oligomer-derived species and showed extensive branching and cyclization, whereas aromatics remained minor. Variation of the N 2 flow rate shifted the recovered product distribution through coupled changes in reactant dilution, nominal contact time, and product stripping. Deactivation was associated mainly with retained oligomer-derived soft coke. These results identify accessible acidity and transport as coupled descriptors for tuning unsaturated jet-fuel-range precursors over hierarchical ZSM-5. Download: Download high-res image (220KB) Download: Download full-size image