A Convenient Synthesis of Core-shell ZSM-5@MoO3 Catalyst for Enhanced Catalytic Properties in Methane Aromatization

摘要

A novel core-shell ZSM-5@MoO3 catalyst was successfully synthesized by the hydrothermal coating strategy, and its physicochemical properties and catalytic properties in methane aromatization were investigated using a physically-blended ZSM-5/MoO3 catalyst as a comparison. Multitechniques including XRD, SEM, TEM, EDS, N-2 adsorption, ICP, IR and IG were employed to investigate the characteristics of methane aromatization reaction and the deactivation of carbon deposits. At the reaction temperature of 700 degrees C and a space velocity of 2400 mL g(-1) h(-1), methane conversion and aromatics selectivity of the core-shell ZSM-5@MoO3 catalyst were 11.3 and 88.1 , respectively, which were higher than those of the physically-blended ZSM-5/MoO3 catalyst by 3.1 and 14.8 , respectively. The special reaction pathway of core (ZSM-5, acid sites)-shell (MoO3, Mo sites) and the relatively close proximity between MoO3 and ZSM-5 were mainly responsible for the excellent properties in the methane aromatization reaction. At the same time, the formation of the micro-mesoporous property accelerated the mass-transfer rate and inhibited the formation of carbonaceous deposition, greatly improving the stability of methane aromatization. Thanks to its core-shell structure, ZSM-5@MoO3 catalyst showed the excellent properties in methane aromatization.