Synthesis and characterization of fibrous silica ZSM-5 for cumene hydrocracking

Abstract

Fibrous silica ZSM-5 (FZSM-5) with a novel dendrimeric morphology was synthesized using a CTAB-based microemulsion system. The dendrimers increased the active site accessibility and enhanced the catalytic activity for large molecule hydrocracking and ethylbenzene dehydrogenation.

Fibrous silica mesoporous ZSM-5 for carbon monoxide methanation

“…However, based on previous literatures, fibrous materials have been applied in other catalytic testing due to its excellent properties. Recently, our research group have studied on the use of fibrous silica ZSM-5 for cumene hydrocracking [53]. Besides, a new family of high-surface area silica nanospheres (KCC-1) with fibrous morphologies was first discovered by…”

Platinum‐promoted fibrous silica Y zeolite with enhanced mass transfer as a highly selective catalyst for n ‐dodecane hydroisomerization

“…This inherent property of fibrous HY@KCC‐1 facilitates smooth diffusion of reactants into the catalyst and products out of it resulting to increased activity over the conventional zeolite catalyst. Increased inter‐dendrimer distance also facilitate better accessibility of active sites by supposedly large reactant molecules . High‐resolution transmission electron microscopy (HRTEM) and H 2 chemisorption were employed to verify the Pt location, particle size, and distribution.…”

“…The mechanism involves enlargement of significant amount of the intrinsic micropores of zeolite Y and the growth of dendrimeric silica fibers onto the zeolitic framework. Microemulsion composed of CTAB as surfactant, butanol as co‐surfactant, and toluene as oil phase and water . On the introduction of the zeolite Y seeds, cationic hydrophilic head of CTAB (CTA + ) advances into the pores as a result of coulombic attraction.…”

“…Vividly, incorporation of Pt metals onto the HY@KCC‐1‐type catalyst has further intensified the Lewis peak significantly because of a possible interaction between the probe and the electron‐deficient Pt metals. Conversely, the increase in intensity of the Brønsted acid peak for Pt/HY catalyst could be attributed to the presence of more bridging hydroxyl groups (SiOHAl) protonating the weakly nucleophilic probe to DMPH + cation …”

Strategies to Enhance the Catalytic Performance of ZSM-5 Zeolite in Hydrocarbon Cracking: A Review

“…The conversion of isopropylbezene cracking over the wool-ball-like ZSM-5 was maintained at 80% even after reaction for 27 h, while that over conventional ZSM-5 decreased to 40% after 10 h [62]. Jalil et al [63] prepared fibrous silica ZSM-5 zeolite (Figure 8) with the feature of high surface area (554 m 2 ·g −1 ), a wide pore diameter (2-20 nm) and abundant strong acid sites by combining the micro-emulsion system and the zeolite crystal-seed crystallization methods. It showed high accessibility and low diffusion limitation for molecules, and excellent activity in cumene, DIPB and TIPB cracking.…”