Next Article in Journal
Polyoxometalate (POM)-Layered Double Hydroxides (LDH) Composite Materials: Design and Catalytic Applications
Next Article in Special Issue
Highly Selective Catalytic Properties of HZSM-5 Zeolite in the Synthesis of Acetyl Triethyl Citrate by the Acetylation of Triethyl Citrate with Acetic Anhydride
Previous Article in Journal
Experimental Research of an Active Solution for Modeling In Situ Activating Selective Catalytic Reduction Catalyst
Previous Article in Special Issue
Nature and Location of Carbonaceous Species in a Composite HZSM-5 Zeolite Catalyst during the Conversion of Dimethyl Ether into Light Olefins
Article Menu
Issue 9 (September) cover image

Export Article

Open AccessFeature PaperArticle
Catalysts 2017, 7(9), 259; doi:10.3390/catal7090259

The Role of Non-Framework Lewis Acidic Al Species of Alkali-Treated HZSM-5 in Methanol Aromatization

1
Department of Chemical Engineering, National Cheng Kung University, Tainan 70101, Taiwan
2
Division of Chemical Engineering, Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu 30011, Taiwan
*
Author to whom correspondence should be addressed.
Received: 5 August 2017 / Revised: 23 August 2017 / Accepted: 23 August 2017 / Published: 1 September 2017
(This article belongs to the Special Issue Zeolites and Catalysis)
View Full-Text   |   Download PDF [6510 KB, uploaded 1 September 2017]   |  

Abstract

Mesoporous HZSM-5 prepared by alkaline treatment (also termed desilication) has drawn significant attention due to its potential in large-scale production and in versatile applications, such as separation and catalysis. Alkali-treated HZSM-5 contains considerable amounts of non-framework (amorphous) Lewis acidic Al species on the external surface, and is deemed to be essential in affecting its catalytic performances. This study intends to clarify the catalytic nature of amorphous Al species of alkali-treated HZSM-5 in methanol aromatization. Physicochemical characterizations, including N2 adsorption, scanning electron microscopy (SEM), X-ray diffraction (XRD), magic-angle-spinning nuclear magnetic resonance (MAS NMR), inductively coupled plasma (ICP) analysis, NH3 temperature-programmed desorption (TPD), and methanol-TPD, were performed. The outcomes showed that non-framework Al promotes the hydride transfer in mesoporous HZSM-5, thereby facilitating the aromatization reaction. Among aromatic products, durene can be promoted by non-framework Al through methylation/transalkylation of other aromatics, particularly xylenes, instead of being promoted by reduced space confinement in mesoporous HZSM-5. View Full-Text
Keywords: aluminum; alkaline treatment; Lewis acid; HZSM-5; methanol aluminum; alkaline treatment; Lewis acid; HZSM-5; methanol
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Supplementary material

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Lai, P.-C.; Hsieh, C.-Y.; Chen, C.-H.; Lin, Y.-C. The Role of Non-Framework Lewis Acidic Al Species of Alkali-Treated HZSM-5 in Methanol Aromatization. Catalysts 2017, 7, 259.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Catalysts EISSN 2073-4344 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top