Influence of template content on selective synthesis of SAPO-18, SAPO-18/34 intergrowth and SAPO-34 molecular sieves used for methanol-to-olefins process

SAPO-18, SAPO-18/34 intergrowth and SAPO-34 molecular sieves have been selective synthesized using different amount of template (tetraethyl ammonium hydroxide, TEAOH). The samples were characterized by XRD, XRF, TG-DSC, 13 C ( 29 Si) CP/MAS NMR and NH 3 -TPD. The synthesized products switched from S...

Full description

Saved in:
Bibliographic Details
Published in:RSC advances 2016-01, Vol.6 (107), p.104985-104994
Main Authors: Wang, Ya, Chen, Sheng-Li, Jiang, Yong-Jie, Cao, Ying-Qian, Chen, Fen, Chang, Wei-Ke, Gao, Yu-Li
Format: Article
Language:English
Subjects:
Ammonium hydroxide
Cages
Ethene
Methyl alcohol
Molecular sieves
NMR spectroscopy
Olefins
Synthesis (chemistry)
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:SAPO-18, SAPO-18/34 intergrowth and SAPO-34 molecular sieves have been selective synthesized using different amount of template (tetraethyl ammonium hydroxide, TEAOH). The samples were characterized by XRD, XRF, TG-DSC, 13 C ( 29 Si) CP/MAS NMR and NH 3 -TPD. The synthesized products switched from SAPO-5/18, to SAPO-18, SAPO-18/34, and finally to SAPO-34 with the increasing of TEAOH amount. The TEAOH in SAPO-18 cages mainly acted the role of space filling. While in SAPO-34, the TEAOH was mainly used to compensate the negative charge of the framework. SAPO-34 possessed much more Si(4Al) structure compared to SAPO-18 and SAPO-18/34. For methanol to olefins reaction, SAPO-18 yielded the highest propene and C 4 than that over SAPO-18/34 and SAPO-34, SAPO-34 had the highest ethene yield among the three catalysts. The working lifetimes of SAPO-18/34 and SAPO-34 were significantly longer than that of SAPO-18.
ISSN:2046-2069
2046-2069
DOI:10.1039/C6RA23048B