Synthesis of hierarchical MFI zeolites with a micro–macroporous core@mesoporous shell structure

Abstract

Core–shell structured ZSM-5 zeolites were synthesized by using a bifunctional surfactant containing alkene group in the hydrophobic tail.

Optimization of hierarchical ZSM-5 structure from kaolin as catalysts for biofuel production

“…Another reason for the low hydrocarbon selectivity on Z9 is the lack of Lewis acidity in crystalline ZSM-5. 31 The hydrocarbon can be further divided into alkane and alkene, which provides a further understanding of the role of the catalyst during deoxygenation. Generally, the selectivity of alkene from all the catalysts was lower than alkane ( Fig.…”

“…Therefore, the template method has been preferred because it produces a larger mesopores between 3-12 nm while maintaining crystalline framework. 21 Hierarchical ZSM-5 was obtained by self-assembly of the aluminosilicate gel to form large pores 21 employing various templates such as tetrapropylammonium hydroxide (TPAOH), 25 tetraethylammonium hydroxide (TEAOH), 26 carbon nano tube, 27 graphene, 28 organosilanes ( [3-(trimethoxysilyl)propyl] ammonium chloride (TPHAC)), 29,30 surfactants (CTAB), [31][32][33] or polymers (polyacrylic acid). 7,34 TPAOH is the most widely employed template for forming hierarchically hollow mesoporous ZSM-5 via a dissolution-recrystallization mechanism.…”

ZSM‐5@KIT‐6‐encapsulated composite molecular sieves for the catalytic cracking of waste cooking oil model compound to produce light olefins

“…Adsorption steps associated with the hysteresis loops can be observed in the moderate relative pressure region (0.45 < P / P 0 < 0.95). These loops originated from capillary condensation in the mesopores of the shells and indicate a broad pore size distribution 31 . KIT‐6, ZK‐50 and ZK‐80 all generated typical type IV isotherms with obvious hysteresis loops.…”

State of the Art and Perspectives of Hierarchical Zeolites: Practical Overview of Synthesis Methods and Use in Catalysis

“…New core-shell structured ZSM-5 zeolites were obtained with a micro-macroporous core and a mesoporous shell. [94] The higher economic cost of customized soft templates is often a drawback for catalytic applications. Meng et al were able to produce mesoporous ZSM-5 using a cheap monoquaternary ammonium surfactant (C 16 H 33 [N + -methylpiperidine]) and diethyl amine (DEA).…”

“…New core–shell structured ZSM‐5 zeolites were obtained with a micro–macroporous core and a mesoporous shell. [ 94 ]…”