Coke Formation on ZSM‑5 Zeolite Catalysts for 1‑Hexene Isomerization

The coke evolution and catalyst deactivation during 1-hexnene isomerization catalyzed by ZSM-5 zeolite catalysts are investigated by combining catalytic experiments and characterization techniques. The formed coke in micropores should be small-sized monophenyl ring compounds (coke precursors) due to the micropore confinement, and the coke precursors on the external surface of ZSM-5 crystals can be turned into polycyclic aromatic hydrocarbons (hard coke). The coke in high-acidity ZSM-5 zeolite almost blocks all the micropores at the early reaction stage (