Effect of zinc introduction on catalytic performance of ZSM-5 in conversion of methanol to light olefins

The effect of Zn on the catalytic performance of ZSM-5 in the methanol-to-olefin conversion was investigated. The samples were characterised by X-ray diffraction, N2 adsorption, FTIR, temperature-programmed desorption of ammonia and water, and Py-IR. The experimental results revealed Znmodified ZSM-5 to show a lower selectivity to light olefin at the higher reaction temperature of 520°C but a higher selectivity to light olefin at lower temperatures. As a comparison, the catalytic performance of Ca-modified ZSM-5 for the methanol conversion is also given. From the above results, it is concluded that Zn may play another role in the methanol conversion in addition to tuning the surface acidic property after modification.