Alcohol-assisted synthesis of high-silica zeolites in the absence of organic structure-directing agents

Article abstract of DOI:10.1016/S1872-2067(20)63677-4

In this work, we show for the first time that high-silica zeolites (MFI, TON, MTT, and *MRE) could be synthesized from a combined strategy of both zeolite seeding and alcohol filling in the absence of organic structure-directing agents (OSDAs). High-silica ZSM-5 zeolites with Si/Al ratios ranging from 38 to 240 (TF-Al-ZSM-5) could be synthesized via this route. The key to the success of this technique was the employment of an aluminosilicate precursor with a fully 4-coordinated aluminum species as the initial source, wherein the rearrangement and condensation of the silicate species, rather than the aluminate species, occurred during zeolite crystallization. In addition, heteroatoms, such as Fe and B, could be incorporated into the zeolite frameworks. Catalytic tests for the methanol-to-propylene (MTP) reaction exhibited good catalytic performance for TF-Al-ZSM-5, which was comparable to that of the aluminosilicate ZSM-5 zeolite synthesized with OSDAs. Hence, this method offers viable opportunities for the industrial production and catalytic application of high-silica zeolites in the future.

Full text of DOI:10.1016/S1872-2067(20)63677-4

Chinese Journal of Catalysis 42 (2021) 563–570
a v a i l a b l e a t w w w . s c i e n c e d i r e c t . c o m
j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / c h n j c
Article
Alcohol‐assisted synthesis of high‐silica zeolites in the absence of
organic structure‐directing agents
Huimin Luana, Chi Leia, Ye Maa, Qinming Wua,*, Longfeng Zhub, Hao Xua, Shichao Hana,
Qiuyan Zhua, Xiaolong Liuc,#, Xiangju Menga, Feng‐Shou Xiaoa,$
a Key Laboratory of Applied Chemistry of Zhejiang Province, Department of Chemistry, Zhejiang University, Hangzhou 310028, Zhejiang, China
b College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing 314001, Zhejiang, China
c School of Material, Sun Yat‐Sen University, Guangzhou 510006, Guangdong, China
A R T I C L E I N F O
A B S T R A C T
Article history:
In this work, we show for the first time that high‐silica zeolites (MFI, TON, MTT, and *MRE) could be
synthesized from a combined strategy of both zeolite seeding and alcohol filling in the absence of
organic structure‐directing agents (OSDAs). High‐silica ZSM‐5 zeolites with Si/Al ratios ranging
from 38 to 240 (TF‐Al‐ZSM‐5) could be synthesized via this route. The key to the success of this
technique was the employment of an aluminosilicate precursor with a fully 4‐coordinated alumi‐
num species as the initial source, wherein the rearrangement and condensation of the silicate spe‐
cies, rather than the aluminate species, occurred during zeolite crystallization. In addition, heteroa‐
toms, such as Fe and B, could be incorporated into the zeolite frameworks. Catalytic tests for the
methanol‐to‐propylene (MTP) reaction exhibited good catalytic performance for TF‐Al‐ZSM‐5,
which was comparable to that of the aluminosilicate ZSM‐5 zeolite synthesized with OSDAs. Hence,
this method offers viable opportunities for the industrial production and catalytic application of
high‐silica zeolites in the future.
Received 8 May 2020
Accepted 25 June 2020
Available online 5 September 2020
Keywords:
Zeolite
High silica
Seed directing
Alcohol filling
Catalytic performance
© 2021, Dalian Institute of Chemical Physics, Chinese Academy of Sciences.
Published by Elsevier B.V. All rights reserved.
1. Introduction
[24–27]. Generally, high‐silica zeolites are synthesized in the
presence of organic structure‐directing agents (OSDAs), such as
Zeolites, particularly high‐silica zeolites, have been exten‐
sively applied in the field of catalysis for decades owing to their
excellent thermal and hydrothermal stabilities, large micropore
volumes, high surface areas, and uniform microporous chan‐
nels [1–27]. For example, high‐silica aluminosilicate ZSM‐5
zeolite is widely used in the methanol‐to‐propylene (MTP)
reaction [22–24], and high‐silica aluminosilicate ZSM‐48 zeolite
is an efficient catalyst for the hydroisomerization of n‐alkanes
quaternary ammonium cations and amines, which direct the
assembly pathway and ultimately fill the zeolite micropores
[8–27]. The employment of these OSDAs not only increases the
cost but also produces a large amount of polluted water. In
addition, the zeolite framework sometimes would deteriorate
during the removal of organic templates due to high tempera‐
ture calcination.
In the past years, great efforts have been made to develop
* Corresponding author. Tel/Fax: +86‐571‐8273698; E‐mail: qinmingwu@zju.edu.cn
# Corresponding author. Tel/Fax: +86‐20‐83642214; E‐mail: liuxlong9@mail.sysu.edu.cn
$ Corresponding author. Tel/Fax: +86‐571‐8273698; E‐mail: fsxiao@zju.edu.cn
This work was supported by the National Key Research and Development Program of China (2017YFB0702803) and the National Natural Science
Foundation of China (21720102001, 91634201, 21703203, 21802053).
DOI: 10.1016/S1872‐2067(20)63677‐4 | http://www.sciencedirect.com/science/journal/18722067 | Chin. J. Catal., Vol. 42, No. 4, April 2021

Chinese Journal of Catalysis, 42 (2021) 563-570. doi:10.1016/S1872-2067(20)63677-4

Chinese Journal of Catalysis, 42 (2021) 563-570. doi:10.1016/S1872-2067(20)63677-4

Chinese Journal of Catalysis, 42 (2021) 563-570. doi:10.1016/S1872-2067(20)63677-4

Chinese Journal of Catalysis, 42 (2021) 563-570. doi:10.1016/S1872-2067(20)63677-4

Chinese Journal of Catalysis, 42 (2021) 563-570. doi:10.1016/S1872-2067(20)63677-4

Chinese Journal of Catalysis, 42 (2021) 563-570. doi:10.1016/S1872-2067(20)63677-4

Chinese Journal of Catalysis, 42 (2021) 563-570. doi:10.1016/S1872-2067(20)63677-4