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synthesis of ordered mesoporous silica sba-15 for

An ordered mesoporous tungsten-oxide/carbon (denoted as m-WO 3-x-C-s) nanocomposite is synthesized using a simple one-pot method using polystyrene-block-poly(ethylene oxide) (PS-b-PEO) as a structure-directing agent. The hydrophilic PEO block interacts with the carbon and tungsten precursors (resol polymer and WCl6), and the PS block is converted to pores after heating at 700 °C under a nitrogen flow. The m-WO 3-x-C-s nanocomposite has a high Brunauer-Emmett-Teller (BET) surface area and hexagonally ordered pores. Because of its mesoporous structure and high intrinsic density of tungsten oxide, this material exhibits a high average volumetric capacitance and gravimetric capacitance as a pseudocapacitor electrode. In comparison with reduced mesoporous tungsten oxide (denoted as m-WO3-x-h), which is synthesized by a tedious hard template approach and further reduction in a H2/N2 atmosphere, m-WO 3-x-C-s shows a high capacitance and enhanced rate performance, as confirmed by cyclic voltammetry, galvanostatic charge/discharge measurements, and electrochemical impedance spectroscopy. The good performance of m-WO 3-x-C-s is attributed to the high surface area arising from the mesoporous structure, the large interconnected mesopores, and the low internal resistance from the well-dispersed reduced tungsten oxide and amorphous carbon composite structure. Here, the amorphous carbon acts as an electrical pathway for effective pseudocapacitor behavior of WO3-x. An ordered mesoporous tungsten-oxide/carbon (m-WO3-x-C-s) nanocomposite is synthesized using a block-copolymer-assisted one-pot self-assembly method. As a pseudocapacitor electrode, m-WO3-x-C-s exhibits a high average volumetric capacitance of 340 F cm-3 and a gravimetric capacitance of 103 F g-1. The amorphous carbon in the m-WO3-x-C-s decreases the internal resistance of m-WO3-x-C-s electrode by facilitating electric conduction.

T1 - Synthesis of ordered mesoporous silica membranes containing iron oxide nanocrystallites

AB - Hexagonally ordered mesoporous AlSBA-15 with different n Si/nAl ratios have been hydrothermally synthesized using the non-ionic copolymer Pluronic P123 surfactant as the structure directing agent and characterized by XRD, N2 adsorption-desorption, and ammonia-temperature programmed desorption (pyridine-TPD). Acetal and acylal formation reactions of organic carbonyl compounds were efficiently catalyzed by AlSBA-15 under liquid-phase reaction conditions and the results were compared with the MFI, BEA and AlMCM-41(23). Of the catalysts studied, A1SBA-15(45) showed the highest activity in both the acetalization and acylal reactions of the carbonyl compounds under the optimized reaction conditions, and could be recycled several times without loss in activity. AlSBA-15(45) catalyst is highly stable, efficient, chemoselective, and environmental friendly, which could open the possibility for environment benign approach for the synthesis of acetals, acylals and its derivatives under mild reaction conditions.

Synthesis of ordered mesoporous | …

T1 - Synthesis of fructone and acylal using hexagonally ordered mesoporous aluminosilicate catalyst

Hexagonally ordered mesoporous AlSBA-15 with different n Si/nAl ratios have been hydrothermally synthesized using the non-ionic copolymer Pluronic P123 surfactant as the structure directing agent and characterized by XRD, N2 adsorption-desorption, and ammonia-temperature programmed desorption (pyridine-TPD). Acetal and acylal formation reactions of organic carbonyl compounds were efficiently catalyzed by AlSBA-15 under liquid-phase reaction conditions and the results were compared with the MFI, BEA and AlMCM-41(23). Of the catalysts studied, A1SBA-15(45) showed the highest activity in both the acetalization and acylal reactions of the carbonyl compounds under the optimized reaction conditions, and could be recycled several times without loss in activity. AlSBA-15(45) catalyst is highly stable, efficient, chemoselective, and environmental friendly, which could open the possibility for environment benign approach for the synthesis of acetals, acylals and its derivatives under mild reaction conditions.

N2 - Hexagonally ordered mesoporous AlSBA-15 with different n Si/nAl ratios have been hydrothermally synthesized using the non-ionic copolymer Pluronic P123 surfactant as the structure directing agent and characterized by XRD, N2 adsorption-desorption, and ammonia-temperature programmed desorption (pyridine-TPD). Acetal and acylal formation reactions of organic carbonyl compounds were efficiently catalyzed by AlSBA-15 under liquid-phase reaction conditions and the results were compared with the MFI, BEA and AlMCM-41(23). Of the catalysts studied, A1SBA-15(45) showed the highest activity in both the acetalization and acylal reactions of the carbonyl compounds under the optimized reaction conditions, and could be recycled several times without loss in activity. AlSBA-15(45) catalyst is highly stable, efficient, chemoselective, and environmental friendly, which could open the possibility for environment benign approach for the synthesis of acetals, acylals and its derivatives under mild reaction conditions.

Synthesis of Ordered Mesoporous Manganese Oxides …

Proper Si/Al molar ratio was critical for the formation of highly ordered mesoporous materials.

N2 - Development of preparation conditions of highly ordered mesoporous SiO2materials(FSM-16) derived from a layered polysilicate has been summarized and a "folded sheets: mechanism for their formation has been presented. When Na ions in the interlayer region of kanemite were exchanged for alkyltrimethylammonium ions, organoammonium/silicate complexes were obtained and mesoporous silica materials were prepared by calcination of those complexes. When the exchange reaction was carried out at a relatively low pH(∼8.5), the exchange ratio was low and highly ordered pore structures of the mesoporous silica could not be confirmed although the formation of uniform pore size was realized. Increasing the pH(∼11.5) improved the exchange ratio and consequently realized highly porous materials with a regular hexagonal array of uniform channels. The condition of high pH(>11.5) increased a fraction of dissolved silica species. Removal of the dissolved species from the system was necessary to prepare pure FSM-16. The improvement of the reguarlity and purity of FSM-16 by increasing the pH and filtration supported the "folded sheets" mechanism for its formation. The Q4/Q3ratios of SiO4tetrahedra in the silicate/organic complexes prepared by the optimum procedure were in good agreement with those calculated by the folded sheets model and the observed N2absorption behavior suggested an uniform pore-size of FSM-16.

AB - Development of preparation conditions of highly ordered mesoporous SiO2materials(FSM-16) derived from a layered polysilicate has been summarized and a "folded sheets: mechanism for their formation has been presented. When Na ions in the interlayer region of kanemite were exchanged for alkyltrimethylammonium ions, organoammonium/silicate complexes were obtained and mesoporous silica materials were prepared by calcination of those complexes. When the exchange reaction was carried out at a relatively low pH(∼8.5), the exchange ratio was low and highly ordered pore structures of the mesoporous silica could not be confirmed although the formation of uniform pore size was realized. Increasing the pH(∼11.5) improved the exchange ratio and consequently realized highly porous materials with a regular hexagonal array of uniform channels. The condition of high pH(>11.5) increased a fraction of dissolved silica species. Removal of the dissolved species from the system was necessary to prepare pure FSM-16. The improvement of the reguarlity and purity of FSM-16 by increasing the pH and filtration supported the "folded sheets" mechanism for its formation. The Q4/Q3ratios of SiO4tetrahedra in the silicate/organic complexes prepared by the optimum procedure were in good agreement with those calculated by the folded sheets model and the observed N2absorption behavior suggested an uniform pore-size of FSM-16.

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Novel synthesis of ordered mesoporous materials ..

AB - An ordered mesoporous tungsten-oxide/carbon (denoted as m-WO 3-x-C-s) nanocomposite is synthesized using a simple one-pot method using polystyrene-block-poly(ethylene oxide) (PS-b-PEO) as a structure-directing agent. The hydrophilic PEO block interacts with the carbon and tungsten precursors (resol polymer and WCl6), and the PS block is converted to pores after heating at 700 °C under a nitrogen flow. The m-WO 3-x-C-s nanocomposite has a high Brunauer-Emmett-Teller (BET) surface area and hexagonally ordered pores. Because of its mesoporous structure and high intrinsic density of tungsten oxide, this material exhibits a high average volumetric capacitance and gravimetric capacitance as a pseudocapacitor electrode. In comparison with reduced mesoporous tungsten oxide (denoted as m-WO3-x-h), which is synthesized by a tedious hard template approach and further reduction in a H2/N2 atmosphere, m-WO 3-x-C-s shows a high capacitance and enhanced rate performance, as confirmed by cyclic voltammetry, galvanostatic charge/discharge measurements, and electrochemical impedance spectroscopy. The good performance of m-WO 3-x-C-s is attributed to the high surface area arising from the mesoporous structure, the large interconnected mesopores, and the low internal resistance from the well-dispersed reduced tungsten oxide and amorphous carbon composite structure. Here, the amorphous carbon acts as an electrical pathway for effective pseudocapacitor behavior of WO3-x. An ordered mesoporous tungsten-oxide/carbon (m-WO3-x-C-s) nanocomposite is synthesized using a block-copolymer-assisted one-pot self-assembly method. As a pseudocapacitor electrode, m-WO3-x-C-s exhibits a high average volumetric capacitance of 340 F cm-3 and a gravimetric capacitance of 103 F g-1. The amorphous carbon in the m-WO3-x-C-s decreases the internal resistance of m-WO3-x-C-s electrode by facilitating electric conduction.

Synthesis of Mesoporous Silica Nanoparticles - …

N2 - An ordered mesoporous tungsten-oxide/carbon (denoted as m-WO 3-x-C-s) nanocomposite is synthesized using a simple one-pot method using polystyrene-block-poly(ethylene oxide) (PS-b-PEO) as a structure-directing agent. The hydrophilic PEO block interacts with the carbon and tungsten precursors (resol polymer and WCl6), and the PS block is converted to pores after heating at 700 °C under a nitrogen flow. The m-WO 3-x-C-s nanocomposite has a high Brunauer-Emmett-Teller (BET) surface area and hexagonally ordered pores. Because of its mesoporous structure and high intrinsic density of tungsten oxide, this material exhibits a high average volumetric capacitance and gravimetric capacitance as a pseudocapacitor electrode. In comparison with reduced mesoporous tungsten oxide (denoted as m-WO3-x-h), which is synthesized by a tedious hard template approach and further reduction in a H2/N2 atmosphere, m-WO 3-x-C-s shows a high capacitance and enhanced rate performance, as confirmed by cyclic voltammetry, galvanostatic charge/discharge measurements, and electrochemical impedance spectroscopy. The good performance of m-WO 3-x-C-s is attributed to the high surface area arising from the mesoporous structure, the large interconnected mesopores, and the low internal resistance from the well-dispersed reduced tungsten oxide and amorphous carbon composite structure. Here, the amorphous carbon acts as an electrical pathway for effective pseudocapacitor behavior of WO3-x. An ordered mesoporous tungsten-oxide/carbon (m-WO3-x-C-s) nanocomposite is synthesized using a block-copolymer-assisted one-pot self-assembly method. As a pseudocapacitor electrode, m-WO3-x-C-s exhibits a high average volumetric capacitance of 340 F cm-3 and a gravimetric capacitance of 103 F g-1. The amorphous carbon in the m-WO3-x-C-s decreases the internal resistance of m-WO3-x-C-s electrode by facilitating electric conduction.

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