A ternary balance of chemical-anchoring/self-assembly/crystallization: The key to the construction of intracrystalline mesopores

摘要

Zeolite Y with intracrystalline mesopores has been synthesized by controlling a ternary balance (chemical anchoring of the template on zeolite framework, mesoporous self-assembly around the template, and crystallization of zeolite Y). The rapid hydrolysis of (CH3O)(3)Si- to-Si-OH and the subsequent linkage to zeolite framework were crucial for the formation of intracrystalline mesopores. The high concentration of OH- in the initial systems favors the self-assembly of well-ordered mesophases due to the high stability of Dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (TPOACl) micelles. The well-ordered mesopores transfer to wormlike because the solubility of TPOACl increase with the decreased alkalinity by prolonging crystallization of zeolite Y. The materials with relatively well crystallized zeolite Y and high mesopores surface area showed better catalytic properties than the conventional Y and alone well-ordered mesoporous materials. The obtained sample exhibited improved catalytic performance in heavy oil cracking. The yield of the light fraction (gasoline + diesel) of the Cat-2 catalysts is 63.4 wt%, much higher than that of Cat-1 (49.9 wt%) and the Coke yield of Cat-2 is 12.1%, much lower than that of Cat-3 (15.2%). (C) 2017 Published by Elsevier Inc.