共 43 条
Improved hydrothermal stability and acidic properties of ordered mesoporous SBA-15 analogs assembled from nanosized ZSM-5 precursors
被引:25
作者:
Xuan Hoan Vu
[1
]
Steinfeldt, Norbert
[1
]
Armbruster, Udo
[1
]
Martin, Andreas
[1
]
机构:
[1] Univ Rostock, Leibniz Inst Katalyse eV, D-18059 Rostock, Germany
关键词:
Mesoporous material;
Acidity;
Preparation;
ZSM-5;
nanoseeds;
Characterization;
PREFORMED ZEOLITE PRECURSORS;
ALUMINOSILICATE MESOSTRUCTURES;
TRIBLOCK COPOLYMER;
MOLECULAR-SIEVE;
SILICA;
FRAMEWORK;
D O I:
10.1016/j.micromeso.2012.05.036
中图分类号:
O69 [应用化学];
学科分类号:
081704 ;
摘要:
Ordered hexagonal mesoporous materials have been successfully synthesized in a two-step process from assembly of pre-formed nanoscale ZSM-5 precursors at elevated temperature by pH adjusting during synthesis. The resulting materials were characterized by small-angle X-ray scattering (SAXS), N-2 adsorption and desorption (BET), transmission electron microscopy (TEM), temperature-programmed desorption of ammonia (NH3-TPD), FIR spectroscopy of pyridine adsorption-desorption (pyr-FTIR), atomic absorption spectroscopy (AAS) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). It was found out that a highly ordered mesoporous material with both improved hydrothermal stability and acidic properties can be optimally prepared at pH 3.5 and 200 degrees C. The ordered mesostructure of such material is well preserved even after steaming at 800 degrees C for 4 h, with little loss in BET specific surface of 10.7% only, while its acidic properties are significantly enhanced in terms of both acid strength and total acidity. These improved properties can be attributed to the synergistic advantages of the use of zeolite nanoseeds, high temperature synthesis and pH adjustment. (C) 2012 Elsevier Inc. All rights reserved.
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页码:120 / 126
页数:7
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