A two-stage tandem process combining CO2 Fischer-Tropsch synthesis (CO2-FTS) with downstream zeolite upgrading 

provides a practical route for converting broad Anderson-Schulz-Flory (ASF)-type hydrocarbons into light olefins. In 

this study, hierarchical MFI zeolites with systematically tuned mesoporosity were synthesized using the amphiphilic 

organosilane [3-(trimethoxysilyl)propyl]hexadecyldimethylammonium chloride (TPHAC) and compared with commercial 

microporous ZSM-5 (Si/Al=15). TPHAC preserved the MFI framework while increasing the external surface area and 

mesopore volume. The upstream K/Fe-Cu-Al catalyst produced a stable ASF-type hydrocarbon stream at 300 °C and 

2.5 MPa. In the temperature-screening tandem reaction, TPHAC-4% showed the best performance, affording the highest

C2-C4 olefin selectivity of 52.34% on a hydrocarbon basis at 500 °C while suppressing BTEX formation. Under the 

150 h long-term operation at the same temperature, it maintained an average C2-C4 olefin selectivity of 56.77% over 

TOS 40–150 h. A 1-octene model reaction reproduced the same trend, indicating that the hierarchical pore structure promoted

light-olefin formation while suppressing competing aromatic pathways. Post-reaction coke analysis further showed 

reduced coke accumulation in the micropores. Overall, the hierarchical pore architecture created a more favorable environment

for light-olefin production