Effect of Gadolinium Introduced HZSM-5 Zeolite on the Products Distribution of MTH Reaction

Abstract

A series of Gd/HZSM-5 catalysts were synthesized by incipient-wetness impregnation method and their surface properties and catalytic performances in methanol to hydrocarbons (MTH) reaction were studied in detail. The addition of gadolinium has little effect on the structure of zeolite and the specific surface area of catalyst. However, with the increase of Gd content, the strong acid density of catalysts shows a monotonously increasing trend and the Gd/HZSM-5 catalysts exhibit high C2–C5 aliphatic hydrocarbon selectivity in MTH reaction which can reach 71.6% over the catalysts with the gadolinium content of 7%. In addition, the Gd/HZSM-5 catalysts exhibit much lower carbon deposition rates than the parent HZSM-5 catalyst in MTH reaction due to the low yield of C9+ aromatics. Thus, the introduction of Gd into the HZSM-5 catalysts can significantly affect the amount of acid on the surface of catalyst, the distribution of reaction products and anticoking ability in MTH reaction.