fulltext.study @t Gmail

Alkali treatment upon MCM-49 zeolite with various contents of HMI in the presence of CTAB and application in anisole acylation with acetic anhydride

Paper ID Volume ID Publish Year Pages File Format Full-Text
39311 45817 2015 10 PDF Available
Title
Alkali treatment upon MCM-49 zeolite with various contents of HMI in the presence of CTAB and application in anisole acylation with acetic anhydride
Abstract

•MCM-49 with various contents of hexamethyleneimine was treated with NaOH and CTAB.•Only crevices were observed on the crystal of materials with more HMI retained.•Intracrystalline mesopores were formed for materials with less or no HMI retained.•OMMs were formed when the amount of dissolved species reached a certain value.•The modified samples showed higher catalytic activity in anisole acylation.

A series of MCM-49 zeolites with various contents of hexamethyleneimine (HMI), obtained by calcination at different temperatures, were alkali-treated in NaOH solution containing cetyltrimethylammonium bromide (CTAB). Changes in structural and acidic properties of the resultant samples were systematically investigated by transmission electron microscopy and scanning electron microscopy (TEM and SEM), X-ray diffraction (XRD), N2 and Ar adsorption/desorption isotherms measurements, ammonia temperature-programmed desorption (NH3-TPD) and pyridine adsorption/desorption followed by infrared measurements (Py-IR), as well as 29Si MAS NMR techniques. It was revealed that only crevices were developed on the crystals of MCM-49 zeolite samples with more HMI, resulting in the increase of acid concentrations; whereas intracrystalline mesopores (ca. 3 nm) could be formed for the samples with less HMI at the expense of framework destruction. A bit of ordered mesoporous materials (OMMs) could also be detected from the latter samples, because the presence of CTAB could induce the re-assembly of dissolved species through the formation of micelle, originating from the desilication by NaOH. When the modified MCM-49 samples were used as catalysts for anisole acylation with acetic anhydride, due to the positive changes in acidities and pore structure properties, they exhibited better catalytic performances for the reaction than the unmodified HMCM-49 catalyst.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (337 K)Download as PowerPoint slide

Keywords
MCM-49 zeolite; Template; Alkali-treatment; CTAB; Acylation
First Page Preview
Alkali treatment upon MCM-49 zeolite with various contents of HMI in the presence of CTAB and application in anisole acylation with acetic anhydride
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 495, 5 April 2015, Pages 152–161
Authors
, , , , , , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us