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Organic‐Free Synthesis of Zeolite Y with High Si/Al Ratios: Combined Strategy of In Situ Hydroxyl Radical Assistance and Post‐Synthesis Treatment
Author(s) -
Wang Jianyu,
Liu Pusheng,
Boronat Mercedes,
Ferri Pau,
Xu Zhaoguo,
Liu Peng,
Shen Baojian,
Wang Zhendong,
Yu Jihong
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202005715
Subject(s) - zeolite , radical , crystallinity , yield (engineering) , hydroxyl radical , catalysis , cumene , chemistry , crystallization , hydrothermal synthesis , citric acid , chemical engineering , hydrothermal circulation , materials science , organic chemistry , crystallography , engineering , metallurgy
Zeolite Y, with a high SiO 2 /Al 2 O 3 ratio (SAR), plays an important role in fluidized catalytic cracking processes. However, in situ synthesis of zeolite Y with high SARs remains a challenge because of kinetic limitations. Here, zeolite Y with an SAR of 6.35 is synthesized by a hydroxyl radical assisted route. Density‐functional theory (DFT) calculations suggest that hydroxyl radicals preferentially enhanced the formation of Si‐O‐Si bonds, thus leading to an increased SAR. To further increase the SAR, a dealumination process was carried out using citric acid, with a subsequent second‐step hydrothermal crystallization, giving an SAR of up to 7.5 while maintaining good crystallinity and high product yield. The resultant zeolite Y shows good performance in cumene cracking. Introduced here is a new strategy for synthesizing high SAR zeolite Y, which is widely used in commercial applications.