Hybrid materials incorporating Eu-(TTA)(3). 2H(2)O (7hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impreg...Hybrid materials incorporating Eu-(TTA)(3). 2H(2)O (7hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impregnation method. The obtained materials were characterized using X-ray diffraction (XRD), IR and diffuse reflectance spectroscopy and luminescence spectra. All the hybrid samples exhibited the characteristic emission bands of EU3+ under UV light excitation at room temperature, and the excitation spectra showed significant blue-shifts compared to the pure rare-earth complex. Although the red emission intensity in the modified hybrid was almost the half of the red emission intensity in the pure Eu-TTA complex at room temperature, the hybrid showed a much higher thermal stability due to the shielding character of the MCM-41 host.展开更多
Active Fe-and Mn-loaded MCM-41(Fe–Mn/MCM-41),which was synthesized via a hydrothermal reaction followed by impregnation,is used in the heterogeneous Fenton reaction to degrade methyl orange(MO) in aqueous solution. T...Active Fe-and Mn-loaded MCM-41(Fe–Mn/MCM-41),which was synthesized via a hydrothermal reaction followed by impregnation,is used in the heterogeneous Fenton reaction to degrade methyl orange(MO) in aqueous solution. The synthesized samples were characterized by X-ray diffraction,scanning electron microscopy,transmission electron microscopy,N_2 adsorption–desorption isotherm analysis,Fourier transform infrared spectroscopy,and X-ray photoelectron spectroscopy. Compared with Fe/MCM-41 and Mn/MCM-41,Fe–Mn/MCM-41 showed higher activity for MO degradation and mineralization. Effects of various operating parameters,such as pH,Mn content,and H_2O_2 dosage,on the degradation process were subsequently investigated. Results of experiments on the effect of radical scavengers revealed that the degradation of MO could be attributed to oxidation by HO_·. The synergy of Fe and Mn species in the Fenton oxidation process was also explained.展开更多
Using cetyl-trimethyl-ammonium bromide （CTMAB） as template and tetraethylortho-silicate （TEOS） as silica source, the MCM-41 mesoporous materials incorporated in framework by Y, Nd and Sm were synthesized by hydrot...Using cetyl-trimethyl-ammonium bromide （CTMAB） as template and tetraethylortho-silicate （TEOS） as silica source, the MCM-41 mesoporous materials incorporated in framework by Y, Nd and Sm were synthesized by hydrothermal synthesis method. The structure, morphology of materials and the state of Y, Nd, Sm in materials were investigated by means of XRD, nitrogen adsorption-desorption, SEM, IR spectrometry, TG-DTA. The XRD results indicate that the samples possess the mesoporous MCM-41 structures with ordered hexagonal arrangements. Y, Nd and Sm ions can get into the framework of mesoporous materials. Nitrogen adsorption desorption isotherms show that the samples have typical mesopores characteristics. SEM micrographs reveal that incorporated sampies show a spherical morphology and the diameters are averagely 0. l0 to 0.15 μm. In IR spectrum of samples, there are the feature adsorption peaks about Si-O-Ln（Ln=Y, Sm, Nd）at 960-985 cm^-1, which affirm that Y, Nd, Sm ions locate in the framework of several mesoporous materials. Results from TG-DTA analysis suggest that two different template sorption sites exist in the framework of YMCM-41, SmMCM-41, NdMCM-41, which powerfully proves that the presence of Y, Nd and Sm in Si framework of the materials.展开更多
Mesoporous silicon oxynitrides MCM-41 were synthesized successfully. The resulting materials not only have high nitrogen contents and good structural characteristics of MCM-41 (high surface area, narrow pore size dist...Mesoporous silicon oxynitrides MCM-41 were synthesized successfully. The resulting materials not only have high nitrogen contents and good structural characteristics of MCM-41 (high surface area, narrow pore size distribution and good order), but also are amorphous. The composition and structure of the materials were investigated by CNH element analysis, XPS, Si MAS NMR, XRD, HRTEM and N-2 sorption, respectively. Mesoporous silicon oxynitrides MCM-41 with a high nitrogen content are still non-crystal (amorphous).展开更多
Surface organometallic chemistry (SOMC) is a recently developing research field. It is of great significance for the quantitative modification, restoration of solid surface, identification of the physical and chemical...Surface organometallic chemistry (SOMC) is a recently developing research field. It is of great significance for the quantitative modification, restoration of solid surface, identification of the physical and chemical nature of surface and the preparation of new catalyst. The production of R 3 Sn-O-MCM-41 (R 3 SnM) was obtained by heating tributyltin chloride and Al-MCM-41 mixture at 170 °C for 5 h under stirring in nitrogen atmosphere. The composition, structure and surface physical and chemical properties of the samples were characterized by inductively coupled plasma mass spectrometry (ICP-MS), 13 C, 119 Sn, 29 Si and 27 Al solid state NMR (nuclear magnetic resonance) spectra, in-situ pyridine infrared spectroscopy (Py-IR), N 2 adsorption-desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), etc. The results of ICP and organic elemental analysis shows that the grafting yield w Sn was 6.46% for R 3 SnM. H 0 (the negative logarithm of the acid concentration)and the number of acid sites for R 3 SnM respectively were 2.77-0.99 and 4.8 mmol·g-1 by the Hammett method. N 2 adsorption-desorption, XRD, TEM analysis showed that R 3 SnM with ordered hexagonal mesopore structure, resulted in the decease of surface areas and pore size as well as the increase of mesoporous volume and surface acidity, as compared to Al-MCM-41. R 3 SnM was used in the synthesis of isoamyl acetate. The yield of isoamyl acetate was 96% when n(isoamyl alcohol)︰n(acetic acid) 1.0︰1.0, 3 R SnM w 5%, 138 °C for 5 h. The catalyst can be reused and the yield of 86% can be attained when catalyst was reused five times at the same catalytic conditions.展开更多
Using cetyl-trimethyl-ammonium bromide （CTMAB） as template agent and tetraethylorthosilicate （TEOS） as silica Source, the MCM-41 mesoporous materials were synthesized with Y, Nd and Sm incorporated in the framewor...Using cetyl-trimethyl-ammonium bromide （CTMAB） as template agent and tetraethylorthosilicate （TEOS） as silica Source, the MCM-41 mesoporous materials were synthesized with Y, Nd and Sm incorporated in the framework under hydrothermal conditions. The structure and the micro-morphology of the materials and the state of Y, Nd and Sm were investigated through the analyses of XRD, nitrogen adsorption-desorption isotherm, SEM, IR and TG-DTA. The XRD resuits indicate that the synthetic samples are of typical structure of mesoporous MCM-41 with ordered hexagonal arrangements, and Y, Nd and Sm can be incorporated into the framework of these mesoporous materials. Nitrogen adsorption-desorption isotherms show that the samples possess the typical mesopores character. SEM micrographs reveal that the incorporated samples show a well-defined spherical morphology with the diameter ranging 0.10 - 0.15μm. The occurrence of two different template sorption sites in the framework as revealed by TG-DTA analysis further suggests the presence of Y, Nd and Sm in siliceous framework.展开更多
Vanadium molybdenum oxynitrides nanoparticles were synthesized successfully in the channels of MCM-41 after surface modification,vacumm co-impregnation and nitridation technology.The products were investigated by nitr...Vanadium molybdenum oxynitrides nanoparticles were synthesized successfully in the channels of MCM-41 after surface modification,vacumm co-impregnation and nitridation technology.The products were investigated by nitrogen sorption measurement,X-ray powder diffraction（XRD）,high-resolution transmission electron microscopy（HRTEM）,energy dispersive analysis of X-rays（EDAX）and CNH element analysis.The investigation resnlts show that superfine nanoparticles of vanadium molybderum oxynitrides exist in the channels of MCM-41.展开更多
A convenient and economic method for preparing highly ordered MCM 41 was studied in an open vessel by using waterglass as the silicon source. XRD, nitrogen adsorption and TEM show that the product has a highly ordered...A convenient and economic method for preparing highly ordered MCM 41 was studied in an open vessel by using waterglass as the silicon source. XRD, nitrogen adsorption and TEM show that the product has a highly ordered structure and the hexagonal arrangements of uniformly size pores distribution.展开更多
In this investigation, MCM 41 mesoporous molecular sieve was firstly synthesized with tetraethyl orthosilicate(TEOS) as the silica source and cetyltrimethyl ammonium bromide(CTMABr) as the template by microwave radiat...In this investigation, MCM 41 mesoporous molecular sieve was firstly synthesized with tetraethyl orthosilicate(TEOS) as the silica source and cetyltrimethyl ammonium bromide(CTMABr) as the template by microwave radiation method (including the processes of crystallization and de template).The product obtaind was characterized by XRD, TG, IR, SEM. The influence of the conditions of microwave radiation on the structure of MCM 41 mesoporous molecular sieve was mainly discussed .The results showed that MCM 41 mesoporous molecular sieve with high purity, good thermal stability and a spherical hexagonal morphology, the diameter of the crystalline particles about 2～10μm was obtained.展开更多
基金financial supportfrom PRAMX 98-05 and helpful discussion with Dr.A.C.Franville.
文摘Hybrid materials incorporating Eu-(TTA)(3). 2H(2)O (7hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impregnation method. The obtained materials were characterized using X-ray diffraction (XRD), IR and diffuse reflectance spectroscopy and luminescence spectra. All the hybrid samples exhibited the characteristic emission bands of EU3+ under UV light excitation at room temperature, and the excitation spectra showed significant blue-shifts compared to the pure rare-earth complex. Although the red emission intensity in the modified hybrid was almost the half of the red emission intensity in the pure Eu-TTA complex at room temperature, the hybrid showed a much higher thermal stability due to the shielding character of the MCM-41 host.
基金supported by the National Basic Research Program of China ("973" Program, No. 2012CB720302)Program for Changjiang Scholars and the Innovative Research Team in Universities (No. IRT0936)
文摘Active Fe-and Mn-loaded MCM-41(Fe–Mn/MCM-41),which was synthesized via a hydrothermal reaction followed by impregnation,is used in the heterogeneous Fenton reaction to degrade methyl orange(MO) in aqueous solution. The synthesized samples were characterized by X-ray diffraction,scanning electron microscopy,transmission electron microscopy,N_2 adsorption–desorption isotherm analysis,Fourier transform infrared spectroscopy,and X-ray photoelectron spectroscopy. Compared with Fe/MCM-41 and Mn/MCM-41,Fe–Mn/MCM-41 showed higher activity for MO degradation and mineralization. Effects of various operating parameters,such as pH,Mn content,and H_2O_2 dosage,on the degradation process were subsequently investigated. Results of experiments on the effect of radical scavengers revealed that the degradation of MO could be attributed to oxidation by HO_·. The synergy of Fe and Mn species in the Fenton oxidation process was also explained.
文摘Using cetyl-trimethyl-ammonium bromide （CTMAB） as template and tetraethylortho-silicate （TEOS） as silica source, the MCM-41 mesoporous materials incorporated in framework by Y, Nd and Sm were synthesized by hydrothermal synthesis method. The structure, morphology of materials and the state of Y, Nd, Sm in materials were investigated by means of XRD, nitrogen adsorption-desorption, SEM, IR spectrometry, TG-DTA. The XRD results indicate that the samples possess the mesoporous MCM-41 structures with ordered hexagonal arrangements. Y, Nd and Sm ions can get into the framework of mesoporous materials. Nitrogen adsorption desorption isotherms show that the samples have typical mesopores characteristics. SEM micrographs reveal that incorporated sampies show a spherical morphology and the diameters are averagely 0. l0 to 0.15 μm. In IR spectrum of samples, there are the feature adsorption peaks about Si-O-Ln（Ln=Y, Sm, Nd）at 960-985 cm^-1, which affirm that Y, Nd, Sm ions locate in the framework of several mesoporous materials. Results from TG-DTA analysis suggest that two different template sorption sites exist in the framework of YMCM-41, SmMCM-41, NdMCM-41, which powerfully proves that the presence of Y, Nd and Sm in Si framework of the materials.
文摘Mesoporous silicon oxynitrides MCM-41 were synthesized successfully. The resulting materials not only have high nitrogen contents and good structural characteristics of MCM-41 (high surface area, narrow pore size distribution and good order), but also are amorphous. The composition and structure of the materials were investigated by CNH element analysis, XPS, Si MAS NMR, XRD, HRTEM and N-2 sorption, respectively. Mesoporous silicon oxynitrides MCM-41 with a high nitrogen content are still non-crystal (amorphous).
基金Supported by the National Science Foundation of Heilongjiang Province (B201010)the Education Department of Heilongjiang Province (12511595)
文摘Surface organometallic chemistry (SOMC) is a recently developing research field. It is of great significance for the quantitative modification, restoration of solid surface, identification of the physical and chemical nature of surface and the preparation of new catalyst. The production of R 3 Sn-O-MCM-41 (R 3 SnM) was obtained by heating tributyltin chloride and Al-MCM-41 mixture at 170 °C for 5 h under stirring in nitrogen atmosphere. The composition, structure and surface physical and chemical properties of the samples were characterized by inductively coupled plasma mass spectrometry (ICP-MS), 13 C, 119 Sn, 29 Si and 27 Al solid state NMR (nuclear magnetic resonance) spectra, in-situ pyridine infrared spectroscopy (Py-IR), N 2 adsorption-desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), etc. The results of ICP and organic elemental analysis shows that the grafting yield w Sn was 6.46% for R 3 SnM. H 0 (the negative logarithm of the acid concentration)and the number of acid sites for R 3 SnM respectively were 2.77-0.99 and 4.8 mmol·g-1 by the Hammett method. N 2 adsorption-desorption, XRD, TEM analysis showed that R 3 SnM with ordered hexagonal mesopore structure, resulted in the decease of surface areas and pore size as well as the increase of mesoporous volume and surface acidity, as compared to Al-MCM-41. R 3 SnM was used in the synthesis of isoamyl acetate. The yield of isoamyl acetate was 96% when n(isoamyl alcohol)︰n(acetic acid) 1.0︰1.0, 3 R SnM w 5%, 138 °C for 5 h. The catalyst can be reused and the yield of 86% can be attained when catalyst was reused five times at the same catalytic conditions.
文摘Using cetyl-trimethyl-ammonium bromide （CTMAB） as template agent and tetraethylorthosilicate （TEOS） as silica Source, the MCM-41 mesoporous materials were synthesized with Y, Nd and Sm incorporated in the framework under hydrothermal conditions. The structure and the micro-morphology of the materials and the state of Y, Nd and Sm were investigated through the analyses of XRD, nitrogen adsorption-desorption isotherm, SEM, IR and TG-DTA. The XRD resuits indicate that the synthetic samples are of typical structure of mesoporous MCM-41 with ordered hexagonal arrangements, and Y, Nd and Sm can be incorporated into the framework of these mesoporous materials. Nitrogen adsorption-desorption isotherms show that the samples possess the typical mesopores character. SEM micrographs reveal that the incorporated samples show a well-defined spherical morphology with the diameter ranging 0.10 - 0.15μm. The occurrence of two different template sorption sites in the framework as revealed by TG-DTA analysis further suggests the presence of Y, Nd and Sm in siliceous framework.
文摘Vanadium molybdenum oxynitrides nanoparticles were synthesized successfully in the channels of MCM-41 after surface modification,vacumm co-impregnation and nitridation technology.The products were investigated by nitrogen sorption measurement,X-ray powder diffraction（XRD）,high-resolution transmission electron microscopy（HRTEM）,energy dispersive analysis of X-rays（EDAX）and CNH element analysis.The investigation resnlts show that superfine nanoparticles of vanadium molybderum oxynitrides exist in the channels of MCM-41.
文摘A convenient and economic method for preparing highly ordered MCM 41 was studied in an open vessel by using waterglass as the silicon source. XRD, nitrogen adsorption and TEM show that the product has a highly ordered structure and the hexagonal arrangements of uniformly size pores distribution.
文摘In this investigation, MCM 41 mesoporous molecular sieve was firstly synthesized with tetraethyl orthosilicate(TEOS) as the silica source and cetyltrimethyl ammonium bromide(CTMABr) as the template by microwave radiation method (including the processes of crystallization and de template).The product obtaind was characterized by XRD, TG, IR, SEM. The influence of the conditions of microwave radiation on the structure of MCM 41 mesoporous molecular sieve was mainly discussed .The results showed that MCM 41 mesoporous molecular sieve with high purity, good thermal stability and a spherical hexagonal morphology, the diameter of the crystalline particles about 2～10μm was obtained.
