High‐Temperature Generalized Synthesis of Stable Ordered Mesoporous Silica‐Based Materials by Using Fluorocarbon–Hydrocarbon Surfactant Mixtures

Han, Yu; Li, Defeng; Zhao, Lan; Song, Jiangwei; Yang, Xiao‐Yu; Li, Nan; Yan, Donghang; Li, Caijin; Wu, Shuo; Xu, Xiaodong; Meng, Xiangju; Lin, Kaifeng; Xiao, Feng‐Shou

doi:10.1002/anie.200351466

Cited by 144 publications

(80 citation statements)

References 28 publications

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“…The absorption bands at 2958 and 2870 cm -1 are assigned to symmetric and asymmetric CH 2 stretching modes, ν s and ν as , in long C 16 hydrocarbon chains of CTA + cations. [9] With an increase in crystallization temperature, the intensity of these two bands decreased by 23.7 and 50.0 % at 165 and 185°C, respectively, thereby indicating that some CTA + ions are thermally decomposed and subsequently removed from the channels.…”

Section: Resultsmentioning

confidence: 99%

High‐Temperature Synthesis and Formation Mechanism of Stable, Ordered MCM‐41 Silicas by Using Surfactant Cetyltrimethylammonium Tosylate as Template

et al. 2010

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International audienceHighly ordered 2D hexagonal mesostructured silicas with thick pore walls have been directly hydrothermally synthesized at high temperatures in a range from 130 to 175 °C by using the new surfactant cetyltrimethylammonium tosylate (CTATos) as template. The mesoporous structure of the synthesized MCM-41 could be maintained after heating it to reflux in boiling water for at least 24 h. The crystallization temperature, the nature of surfactants, and the relative amount of TAAOH (tetraalkylammonium hydroxide, such as TMAOH and TEAOH) to surfactant were found to be critical parameters that affect the ordering of mesophases. On the basis of the combined characterizations of X-ray diffraction (XRD), N2 adsorption, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG), 13C cross-polarization magic-angle spinning (CPMAS) solid-state NMR spectroscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM), a new mechanism was proposed to understand the formation mechanism of highly ordered MCM-41 silicas. The enlargement of pore-wall thickness is attributed to the migration and subsequent deposition of the silicate species in the inner pore channel. This process was accelerated by the ion-exchange interaction of tetraalkylammonium cations (TAA+) on CTA+ cations

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Section: Resultsmentioning

confidence: 99%

High‐Temperature Synthesis and Formation Mechanism of Stable, Ordered MCM‐41 Silicas by Using Surfactant Cetyltrimethylammonium Tosylate as Template

et al. 2010

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“…Notably, the 2D hexagonal JLU-20 (p6 mm) was successfully synthesized at the ultra-high temperature of 190 8C and its structure was still highly ordered. [15] In this case, however, the structural ordering of cubic JLU-21 will be destroyed substantially if the synthesis temperature used is more than 140 8C, as shown by the results of XRD and N 2 adsorption investigations above. This may be explained by the structural difference between JLU-20 and JLU-21.…”

mentioning

confidence: 91%

“…[15] We report herein details of the synthesis, structure, characterization, and excellent thermal, hydrothermal, and mechanical stability of JLU-20. Furthermore, when the fluorocarbon surfactant FC-4 is mixed with F127 (EO 106 PO 70 EO 106 ) and this mixture is used as the template, highly ordered cubic mesoporous silica materials with unusual hydrothermal stability, designated JLU-21, are successfully synthesized at high temperatures (140-200 8C).…”

Section: Introductionmentioning

confidence: 99%

High‐Temperature Synthesis of Stable Ordered Mesoporous Silica Materials by Using Fluorocarbon–Hydrocarbon Surfactant Mixtures

Han

Song

et al. 2004

Chemistry A European J

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Highly ordered hexagonal mesoporous silica materials (JLU-20) with uniform pore sizes have been successfully synthesized at high temperature (150-220 degrees C) by using fluorocarbon-hydrocarbon surfactant mixtures. The fluorocarbon-hydrocarbon surfactant mixtures combine the advantages of both stable fluorocarbon surfactants and ordered hydrocarbon surfactants, giving ordered and stable mixed micelles at high temperature (150-220 degrees C). Mesoporous JLU-20 shows extraordinary stability towards hydrothermal treatment (100 % steam at 800 degrees C for 2 h or boiling water for 80 h), thermal treatment (calcination at 1000 degrees C for 4 h), and toward mechanical treatment (compressed at 740 MPa). Transmission electron microscopy images of JLU-20 show well-ordered hexagonal arrays of mesopores with one-dimensional (1D) channels and further confirm that JLU-20 has a two-dimensional (2D) hexagonal (P6 mm) mesostructure. 29Si HR MAS NMR spectra of as-synthesized JLU-20 shows that JLU-20 is primarily made up of fully condensed Q4 silica units (delta=-112 ppm) with a small contribution from incompletely cross-linked Q3 (delta=-102 ppm) as deduced from the very high Q4/Q3 ratio of 6.5, indicating that the mesoporous walls of JLU-20 are fully condensed. Such unique structural features should be directly attributed to the high-temperature synthesis, which is responsible for the observed high thermal, hydrothermal, and mechanical stability of the mesoporous silica materials with well-ordered hexagonal symmetry. Furthermore, the concept of "high-temperature synthesis" is successfully extended to the preparation of three-dimensional (3D) cubic mesoporous silica materials by the assistance of a fluorocarbon surfactant as a co-template. The obtained material, designated JLU-21, has a well-ordered cubic Im3m mesostructure with fully condensed pore walls and shows unusually high hydrothermal stability, as compared with conventional cubic mesoporous silica materials such as SBA-16.

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“…Great efforts have been made to improve the hydrothermal stability of Al-containing mesoporous materials, such as postsynthesis grafting, synthesis of mesoporous materials with thick pore walls, synthesis of mesoporous materials with semicrystalline walls, preparing mesoporous aluminosilicates from performed zeolite nanoclusters, generating microporous zeolitemesostructure, and synthesis of ultrastable mesoporous materials at high temperature. [8][9][10][11][12][13][14] However, the synthesis of Al-containing mesoporous material with high hydrothermal stability remains a big challenge. Previous studies show PMOs exhibit extremely high stability in boiling water.…”

Section: Introductionmentioning

confidence: 99%

Hydrothermal Stability and Catalytic Activity of Aluminum-Containing Mesoporous Ethane−Silicas

Yang

Zhang

et al. 2004

J. Phys. Chem. B

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Aluminum was incorporated into the mesoporous framework of ethane-silica by one-pot condensation of Al(OiPr) 3 with 1,2-bis(trimethoxysilyl)ethane using octadecyltrimethylammonium chloride as surfactant. Powder X-ray diffraction patterns, nitrogen sorption analysis, and TEM results reveal the formation of an ordered mesoporous material with uniform porosity. 27 Al MAS NMR confirms the incorporation of aluminum in the framework. The synthesized materials exhibit extremely high hydrothermal stability in boiling water (no obvious change of mesostructure and textural properties was observed even after refluxing in water for 100 h), which could be mainly contributed to the ethane-bridged mesoporous framework. The aluminum-containing mesoporous ethane-silicas are efficient catalysts for the alkylation of 2,4-di-tert-butylphenol by cinnamyl alcohol to yield a flavan.

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High‐Temperature Generalized Synthesis of Stable Ordered Mesoporous Silica‐Based Materials by Using Fluorocarbon–Hydrocarbon Surfactant Mixtures

Cited by 144 publications

References 28 publications

High‐Temperature Synthesis and Formation Mechanism of Stable, Ordered MCM‐41 Silicas by Using Surfactant Cetyltrimethylammonium Tosylate as Template

High‐Temperature Synthesis and Formation Mechanism of Stable, Ordered MCM‐41 Silicas by Using Surfactant Cetyltrimethylammonium Tosylate as Template

High‐Temperature Synthesis of Stable Ordered Mesoporous Silica Materials by Using Fluorocarbon–Hydrocarbon Surfactant Mixtures

Hydrothermal Stability and Catalytic Activity of Aluminum-Containing Mesoporous Ethane−Silicas

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