Improved performance of hierarchical porous Mo/H-IM-5 catalyst in methane non-oxidative aromatization

Abstract

Two novel hierarchical porous IM-5-S and IM-5-M materials were synthesized using mesoporous silica SBA-15 and MCM-48 as the silica sources, and for comparison conventional IM-5-C zeolite was also synthesized with the same synthesis composition. IM-5-S and IM-5-M samples exhibited larger crystal sizes and different textural properties than the conventional IM-5-C zeolite. Moreover, Mo-modified catalysts, Mo-IM-5-S, Mo-IM-5-M, and Mo-IM-5-C, were prepared for the non-oxidative aromatization of methane. The physical properties and acidities of the samples were characterized by XRD, SEM, TEM, BET, and NH 3 -TPD. Compared with Mo-IM-5-C, the Mo-IM-5-S and Mo-IM-5-M catalysts showed higher yields of aromatics and better stabilities. The preferable catalytic behaviors of Momodified mesoporous IM-5 catalysts may be attributed to the generation of secondary mesoporous systems within the zeolite crystals, which may influence the location and state of the active Mo species, simultaneously lead to easier access to the active sites for reactants and be favorable for the diffusion of products formed in the microporous channels during the methane aromatization reaction.

Investigation of the Properties of Mo/ZSM-5 Catalysts Based on Zeolites With Microporous and Micro-Mesoporous Structure

“…Obtaining catalysts based on zeolites with a micro-mesoporous structure is an urgent problem and opens new possibilities for their application [19,20]. In recent years, the attention of many research groups has been directed to the creation of zeolite-containing catalysts with an additional mesoporous structure [19,[21][22][23][24][25][26]. The synthesis of zeolite of the ZSM-5 type with an ordered hierarchical pore system is a promising direction for obtaining a catalyst with higher activity and stability in the methane dehydroaromatization reaction compared to microporous zeolite.…”

Investigation of the Properties of Mo/ZSM-5 Catalysts Based on Zeolites with Microporous and Micro–Mesoporous Structures

“…Obtaining catalysts based on zeolites with a micro-mesoporous structure is an urgent problem and opens new possibilities for their application [19,20]. In recent years, the attention of many research groups has been directed to the creation of zeolite-containing catalysts with an additional mesoporous structure [19,[21][22][23][24][25][26]. The synthesis of zeolite of the ZSM-5 type with an ordered hierarchical pore system is a promising direction for obtaining a catalyst with higher activity and stability in the methane dehydroaromatization reaction than microporous zeolite.…”