Comparison of disordered mesoporous alumino silicates with highly ordered Al-MCM-41 on stability, acidity and catalytic activity

Citation
Dy. Zhao et al., Comparison of disordered mesoporous alumino silicates with highly ordered Al-MCM-41 on stability, acidity and catalytic activity, CATAL TODAY, 68(1-3), 2001, pp. 11-20
Citations number
32
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
CATALYSIS TODAY
ISSN journal
0920-5861 → ACNP
Volume
68
Issue
1-3
Year of publication
2001
Pages
11 - 20
Database
ISI
SICI code
0920-5861(20010701)68:1-3<11:CODMAS>2.0.ZU;2-Q
Abstract
A simple procedure has been described to directly synthesize hydrothermally stable, disordered mesoporous aluminosilicate materials with strong surfac e acidity by using a polymer aluminosilicate precursor, and cationic surfac tant cetyltrimethylammonium bromide (CTAB) as the structure-directing agent . The comparison of stability, acidity and catalytic activity for the disor dered mesoporous materials and Al-MCM-41 has been studied by X-ray diffract ion (XRD), transmission electron microscopy (TEM), N-2 adsorption/desorptio n, infrared spectra, NH3-temperature program desorption (NH3-TPD) and Al-27 MAS NMR techniques. The results show that the disordered mesoporous materi als are very similar to mesoporous material MCM-41 as regards its uniform m esopore sizes at the mean value of 3.0 nm, while the mesoporous channel arr angement is fully disordered similar to that for KIT-1 prepared by the addi tive of organic salts. Scanning electron microscopic (SEM) images show that the products have regular microscopic arrays and layer sheet-like morpholo gy. The disordered mesoporous materials are hydrothermally more stable than highly ordered MCM-41. Furthermore, they show stronger acid strength and h igher cracking activities than Al-containing MCM-41. (C) 2001 Elsevier Scie nce B.V. All rights reserved.