Highly Selective MTO Reaction over a Nanosized ZSM-5 Zeolite Modified by Fe via the Low-Temperature Dielectric Barrier Discharge Plasma Method

Abstract

Nanosized ZSM-5 zeolites were synthesized by an in situ seed-induced hydrothermal method, and samples modified with an Fe promoter were prepared by the traditional wet impregnation-thermal decomposition and dielectric barrier discharge plasma (DBD) methods, respectively. The physico-chemical properties of the catalysts were studied by XRD, SEM, TEM, BET, XPS, H2-TPR, NH3-TPD and Py-IR techniques. The catalytic performance was eValuated by the methanol-to-olefin (MTO) reaction. The results showed that the acidity of the catalysts, the dispersity of the Fe promoter and the interaction degree with the ZSM-5 zeolite are closely related to product selectivity in the MTO reaction. Compared with the Fe-NZ5 sample prepared by the traditional impregnation-calcination method, the FeD-NZ5 samples prepared by the DBD method exhibited the higher selectivity of C2—C4 light olefins and the lower coke deposition during long-term eValuation (100 h), which can be attributed to the weaker acid strength, more uniform Fe promoter dispersion and strong interaction with the ZSM-5 zeolite. The developed Fe-modified catalysts have high potential for application in the MTO reaction.