Synthesis and Characterization of Hierarchical ZSM-5 Zeolites with Outstanding Mesoporosity and Excellent Catalytic Properties

Abstract

A novel soft-template (ST) is fabricated and successfully employed as mesoporogen to synthesis hierarchical ZSM-5 zeolites with outstanding mesoporosity and high hierarchy factors. The as-produced soft-template can connect steadily with the MFI frameworks by covalent bonds of –Si–O–Si– during the high-temperature hydrothermal crystallization process. This type of connection mode can effectively avoid the formation of amorphous materials, and the specific structure of this soft-template can efficiently introduce plentiful of mesopores with few micropores being consumed. The particles of as-synthesized hierarchical ZSM-5 zeolites are in size of about 1 μm, which are made up of nanocrystals of 60–150 nm. The structure parameters of these samples are characterized with the techniques of X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, nitrogen sorption, scanning electron microscope (SEM), transmission electron microscope (TEM), NH3 temperature-programmed desorption (NH3-TPD) and thermogravimetric (TG). Due to the nature of zeolites and great microporosity, these hierarchical samples present great tolerance of hydrothermal treatment. And because of the intracrystalline mesopores, large external surface areas, and abundant accessible acid sites, whether in conversion rate of reactants or selectivity of products, the hierarchical samples exhibit excellent catalytic performance in the reactions of alkylation between benzene and benzyl alcohol, cracking of 1,3,5-tri-isopropylbenzene, and thermal cracking of low-density polyethylene (LDPE), respectively.Electronic supplementary materialThe online version of this article (10.1186/s11671-018-2779-8) contains supplementary material, which is available to authorized users.

Dextran mediated MnFe2O4/ZnS magnetic fluorescence nanocomposites for controlled self-heating properties

“…The research on magnetic/uorescent nanocomposites has attained signicant potential in numerous technological applications such as catalysis, [1][2][3][4][5] devices, [6][7][8][9][10][11][12] and so on. [13][14][15][16][17][18][19] Recently, due to their exciting magnetic and optical properties the development of opto-magnetic nanocomposites has provided new opportunities for biomedical application such as effective targeted and real-time monitoring drug delivery systems, 20 labelling tissues in vivo for MRI imaging, 21 uorescent markers used to track the migration and anchoring of drugs in cells [22][23][24] and magnetic hyperthermia.…”

Catalytic Production of Methyl Lactate from Fructose‐Based Carbohydrates Using Yttrium Modified ZSM‐5 Zeolite

“…The shoulder band at about 1225 cm −1 and the strong absorbance band at about 1093 cm −1 were belonged to the external Si−O asymmetrical stretching vibration and internal Si−O asymmetrical stretching vibration, respectively [29] . The existence of weak absorbance bands at 798 and 478 cm −1 , which were assigned to the symmetrical stretching and Si−O bending, respectively, indicated the formation of Si−O tetrahedrons from the solid materials by heating [28,29c] . In the meantime, the distorted double five‐membered‐ring (DDR5) structure could also be confirmed through the absorbance band at 548 cm −1 [28,29c] .…”

State of the Art and Perspectives of Hierarchical Zeolites: Practical Overview of Synthesis Methods and Use in Catalysis

“…For instance, an organosilane with three alkyl chains and three silicon atoms on each chain, resulted in catalysts made up of 60-150 nm crystals. [210] Nanoaggregates can also be synthesized using other diverse soft templates, such as nitrogen-containing organics. The group of Shen et al aimed to synthesize ordered 2D mesoporous MFI zeolites, and they achieved this by inserting azobenzene in the hydrophobic tail of the surfactant.…”

“…For instance, an organosilane with three alkyl chains and three silicon atoms on each chain, resulted in catalysts made up of 60–150 nm crystals. [ 210 ]…”