A mesoporous Al-Mg composite oxide with a hexagonal structure was synthesized with aluminium nitrate and magnesium nitrate as the reagents and sodium dodecyl sulfate（SDS） as the template in the presence of ethylened...A mesoporous Al-Mg composite oxide with a hexagonal structure was synthesized with aluminium nitrate and magnesium nitrate as the reagents and sodium dodecyl sulfate（SDS） as the template in the presence of ethylenediamine. The XRD, nitrogen adsorption-desorption and TEM studies indicate that the composite has a hexagonal framework structure and an average pore diameter of 2. 6 nm. The TG/DTA spectra indicate that the decomposition and the removal of the occluded surfactant of the sample take place in a range of 230-550 ℃. The mesoporous Al-Mg composite oxide exhibites a highly catalytic activity for the oxyethylation of fatty alcohols. Narrow-range distributed ethoxylates are formed in the presence of the mesoporous Al-Mg composite oxide catalyst. The distribution selectivity coefficient（Cx） is 24 when the mesoporous Al-Mg composite oxide was used as a catalyst for the oxyethylation of octanol and the average adduct degree of ethoxylates is 6. 4.展开更多
A novel mesoporous HPMo/SiO2 composite was synthesized by the sol-gel method with triblock copolymer EO20PO70EO20 as template.The properties of the product were characterized by X-ray diffraction,transmission electron...A novel mesoporous HPMo/SiO2 composite was synthesized by the sol-gel method with triblock copolymer EO20PO70EO20 as template.The properties of the product were characterized by X-ray diffraction,transmission electron microscopy,N2 adsorption-desorption isotherms,Fourier transform infrared spectrometer and inductively-coupled plasma analysis.The experimental results show that the product has a very ordered hexagonal mesostructure,and the HPMo is immobilized into the framework of silica.The final mesoporous composite shows excellent stability in polar solvents.Results of catalytic tests indicate that the composite is an effective catalyst for oxidation of dibenzothiophen,and there are few activity losses even after the third cycle of uses.The high catalytic activity and good insolubility make it a promising catalyst in oxidative desulfurization process.展开更多
The lanthanum aluminum mesoporous materials were synthesized using sodium dodecyl sulfate as a template agent by ultrasonic hydrothermal method.The resulting samples were characterized by low angle X-ray diffraction（...The lanthanum aluminum mesoporous materials were synthesized using sodium dodecyl sulfate as a template agent by ultrasonic hydrothermal method.The resulting samples were characterized by low angle X-ray diffraction（XRD）,N2 adsorption-desorption studies,transmission electron microscopy（TEM）and surface morphology analysis（SEM）,surface acid（NH3-TPD）,reducibility properties（TPR）,X-ray energy dispersive spectrometer（EDS）and thermogravimetric analysis（TG/DTG）.A l/La composite mesoporous material were synthesized with n（Al）︰n（La）=70︰1.0,80°C of reaction temperature,20 h of reaction time,12 h of crystallization time,650°C of calcination temperature.The specific surface area of the sample is 273.90 m 2 ·g ？1 ,with the average diameter 5.642 nm and pore volume 0.2354 cm 3 ·g ？1 .The samples have mesoporous structure and its particles are similar to a worm-shaped tubular structure.The influence of calcination temperature on the surface physical and chemical properties of Al/La composited mesoporous materials was examined,and the results showed that the acid strength was increased but the amount of acidic sites is decreased as the calcination temperature increased.It was found that the sample calcined at 650°C had appropriate acid content,acid strength and better reducibility.展开更多
Mg-Al layered double hydroxides (LDH) with different particle sizes were prepared using different aging times at high supersaturation by a new method developed in our laboratory. The key features of this method are a ...Mg-Al layered double hydroxides (LDH) with different particle sizes were prepared using different aging times at high supersaturation by a new method developed in our laboratory. The key features of this method are a very rapid mixing and nucleation process followed by a separate aging process. By calcination of LDH at 500°C, mesoporous Mg-Al composite oxides with an extremely narrow pore size distribution were produced. The crystal structure of the Mg-Al composite oxides was a multiphasic one consisting of MgO-like crystals and a layered material.展开更多
In this article,graphene oxide(GO)and benzotriazole-loaded mesoporous silica nanoparticles(BTA/MSNs)are combined on micro scale through the in situ polymerization of polydopamine(PDA),preparing a selfhealing bi-functi...In this article,graphene oxide(GO)and benzotriazole-loaded mesoporous silica nanoparticles(BTA/MSNs)are combined on micro scale through the in situ polymerization of polydopamine(PDA),preparing a selfhealing bi-functional GO(fGO)used as nano-fillers for anti-corrosion enhancement of waterborne epoxy(WEP)coatings.Scanning electronic microscopy(SEM)images show that the BTA/MSNs are uniformly distributed on the surface of high aspect ratio GO nanosheets to endow GO nanocontainer characteristics.UV-vis profiles demonstrate that fGO has p H-controlled release function.Modulus at lowest frequency is generally used for comparing the corrosion resistance of organic coatings.Modulus at lowest frequency(1.42×10^(5)Ωcm^(2))after 30 days immersion in 3.5 wt.%Na Cl solution revealed 2 orders of magnitude higher that of blank WEP(1.17×10^(7)Ωcm^(2)).With artificial cracks on its coatings,fGO/WEP had no obvious rust compared with blank WEP after 240 h of immersion.We anticipate that self-healing and physical barrier bi-functional nanocontainers improve the traditional anticorrosion coating efficiency with better,longer-lasting performance for shipping,oil drilling or bridge maintenance.展开更多
Mesoporous CeO2-MnOx binary oxides with different Mn/Ce molar ratios were prepared by hydrothermal synthesis and characterized by scanning electron microscopy （SEM）, N2 sorption, X-ray diffraction （XRD）, X-ray pho...Mesoporous CeO2-MnOx binary oxides with different Mn/Ce molar ratios were prepared by hydrothermal synthesis and characterized by scanning electron microscopy （SEM）, N2 sorption, X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and H2 temperature-programmed reduction （H2-TPR）. The characterization results indicated that the CeO2-MnOx catalysts exhibited flower-like microspheres with high specific surface areas, and partial Mn cations could be incorporated into CeO2 lattice to form solid solution. The CeO2-MnOx catalysts showed better catalytic activity for CO oxidation than that prepared by the coprecipitation method. Furthermore, the CeO2-MnOx catalyst with Mn/Ce molar ratio of 1 in the synthesis gel （Ce-Mn-1） exhibited the best catalytic activity, over which the conversion of CO could achieve 90% at 135 ℃. This was ascribed to presence of more Mn species with higher oxida- tion state on the surface and the better reducibility over the Ce-Mn-I catalyst than other CeO2-MnOx catalysts.展开更多
Nanocomposites of ZnO encapsulated in mesoporous silica were prepared by wetness impregnation and calcination. The samples were characterized by X-ray diffraction, transmission electron microscopy, nitrogen adsorption...Nanocomposites of ZnO encapsulated in mesoporous silica were prepared by wetness impregnation and calcination. The samples were characterized by X-ray diffraction, transmission electron microscopy, nitrogen adsorption-desorption isotherms, and X-ray photoelectron spectroscopy. The effects of ZnO content and thermal treatment on the existing form of ZnO as well as phase transformation were investigated. ZnO exists stably in the form of non-crystalline phase or cluster when crystallite size is small. With increasing ZnO content, as the size of ZnO reaches a critical size of crystalline phase, the non-crystalline ZnO or cluster transforms structurally to crystalline ZnO with low energy state. Besides, Zn2Si04 was obtained by solid-state reaction between ZnO and rnesoporous silica. The mesoporous silica acts as not only a reactant but also a diffusion barrier which inhibits the phase transformation from ^-Zn2Si04 to ^-Zn2Si04. The formation temperature of Zn2Si04 is lower than that of conventional solid-state reaction because of the unique structure of mesoporous silica.展开更多
Hollow spheres of Si/Al composite oxide with mesopores in the shell wall were prepared by combining O/W/O emulsion with sol-gel process. In this study, TEOS and aluminum isopropylate were used as silicon resource and ...Hollow spheres of Si/Al composite oxide with mesopores in the shell wall were prepared by combining O/W/O emulsion with sol-gel process. In this study, TEOS and aluminum isopropylate were used as silicon resource and aluminum resource, respectively. As an additive, PEG-20000 was added into the inorganic precursors. TEM and N2 adsorption-desorption isotherms indicate the presence of mesopores with uniform pore size in the shell wall. The diameter, shell thickness and hollow structure property of the spheres were characterized by transmission polarized light microscopy and SEM. （）27Al MAS NMR spectrum shows that the coordinated number of the aluminum species is four. The influences on special morphology under different oil phase and reaction temperature were also investigated. The hollow spheres exhibit high thermal stability and can remain their intact spherical structures even after calcination at 550 ℃ for 6 h. This strategy can be extended to synthesize hollow spheres of other binary composite oxide with mesopores.展开更多
基金Supported by the Natural Science Foundation of Heilongjiang Province(No.9810B).
文摘A mesoporous Al-Mg composite oxide with a hexagonal structure was synthesized with aluminium nitrate and magnesium nitrate as the reagents and sodium dodecyl sulfate（SDS） as the template in the presence of ethylenediamine. The XRD, nitrogen adsorption-desorption and TEM studies indicate that the composite has a hexagonal framework structure and an average pore diameter of 2. 6 nm. The TG/DTA spectra indicate that the decomposition and the removal of the occluded surfactant of the sample take place in a range of 230-550 ℃. The mesoporous Al-Mg composite oxide exhibites a highly catalytic activity for the oxyethylation of fatty alcohols. Narrow-range distributed ethoxylates are formed in the presence of the mesoporous Al-Mg composite oxide catalyst. The distribution selectivity coefficient（Cx） is 24 when the mesoporous Al-Mg composite oxide was used as a catalyst for the oxyethylation of octanol and the average adduct degree of ethoxylates is 6. 4.
基金Funded by the Hubei Provincial Department of Education Science and Technology Program for Outstanding Young Talents (Q20081209)
文摘A novel mesoporous HPMo/SiO2 composite was synthesized by the sol-gel method with triblock copolymer EO20PO70EO20 as template.The properties of the product were characterized by X-ray diffraction,transmission electron microscopy,N2 adsorption-desorption isotherms,Fourier transform infrared spectrometer and inductively-coupled plasma analysis.The experimental results show that the product has a very ordered hexagonal mesostructure,and the HPMo is immobilized into the framework of silica.The final mesoporous composite shows excellent stability in polar solvents.Results of catalytic tests indicate that the composite is an effective catalyst for oxidation of dibenzothiophen,and there are few activity losses even after the third cycle of uses.The high catalytic activity and good insolubility make it a promising catalyst in oxidative desulfurization process.
文摘The lanthanum aluminum mesoporous materials were synthesized using sodium dodecyl sulfate as a template agent by ultrasonic hydrothermal method.The resulting samples were characterized by low angle X-ray diffraction（XRD）,N2 adsorption-desorption studies,transmission electron microscopy（TEM）and surface morphology analysis（SEM）,surface acid（NH3-TPD）,reducibility properties（TPR）,X-ray energy dispersive spectrometer（EDS）and thermogravimetric analysis（TG/DTG）.A l/La composite mesoporous material were synthesized with n（Al）︰n（La）=70︰1.0,80°C of reaction temperature,20 h of reaction time,12 h of crystallization time,650°C of calcination temperature.The specific surface area of the sample is 273.90 m 2 ·g ？1 ,with the average diameter 5.642 nm and pore volume 0.2354 cm 3 ·g ？1 .The samples have mesoporous structure and its particles are similar to a worm-shaped tubular structure.The influence of calcination temperature on the surface physical and chemical properties of Al/La composited mesoporous materials was examined,and the results showed that the acid strength was increased but the amount of acidic sites is decreased as the calcination temperature increased.It was found that the sample calcined at 650°C had appropriate acid content,acid strength and better reducibility.
基金This work was supported by the Sinopec (Grant No. X599012).
文摘Mg-Al layered double hydroxides (LDH) with different particle sizes were prepared using different aging times at high supersaturation by a new method developed in our laboratory. The key features of this method are a very rapid mixing and nucleation process followed by a separate aging process. By calcination of LDH at 500°C, mesoporous Mg-Al composite oxides with an extremely narrow pore size distribution were produced. The crystal structure of the Mg-Al composite oxides was a multiphasic one consisting of MgO-like crystals and a layered material.
基金supported by the National Natural Science Foundation of China(Grant No.51908031)the China Scholarship Council for a graduate fellowship(201906150013)+2 种基金the support from Guangdong Special Support Program(Grant No.2017TX04N371)ERC Enercapsule project(647969)Royal Society project IECR2202163。
文摘In this article,graphene oxide(GO)and benzotriazole-loaded mesoporous silica nanoparticles(BTA/MSNs)are combined on micro scale through the in situ polymerization of polydopamine(PDA),preparing a selfhealing bi-functional GO(fGO)used as nano-fillers for anti-corrosion enhancement of waterborne epoxy(WEP)coatings.Scanning electronic microscopy(SEM)images show that the BTA/MSNs are uniformly distributed on the surface of high aspect ratio GO nanosheets to endow GO nanocontainer characteristics.UV-vis profiles demonstrate that fGO has p H-controlled release function.Modulus at lowest frequency is generally used for comparing the corrosion resistance of organic coatings.Modulus at lowest frequency(1.42×10^(5)Ωcm^(2))after 30 days immersion in 3.5 wt.%Na Cl solution revealed 2 orders of magnitude higher that of blank WEP(1.17×10^(7)Ωcm^(2)).With artificial cracks on its coatings,fGO/WEP had no obvious rust compared with blank WEP after 240 h of immersion.We anticipate that self-healing and physical barrier bi-functional nanocontainers improve the traditional anticorrosion coating efficiency with better,longer-lasting performance for shipping,oil drilling or bridge maintenance.
基金supported by National Basic Research Program of China(2010CB732300,2013CB933201)National High Technology Research and Development Program of China(2011AA03A406,2012AA062703)+2 种基金the National Natural Science Foundation of China(21103048,21273150)Shu Guang Project of Shanghai Municipal Education CommissionShanghai Education Development Foundation(10SG30)
文摘Mesoporous CeO2-MnOx binary oxides with different Mn/Ce molar ratios were prepared by hydrothermal synthesis and characterized by scanning electron microscopy （SEM）, N2 sorption, X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and H2 temperature-programmed reduction （H2-TPR）. The characterization results indicated that the CeO2-MnOx catalysts exhibited flower-like microspheres with high specific surface areas, and partial Mn cations could be incorporated into CeO2 lattice to form solid solution. The CeO2-MnOx catalysts showed better catalytic activity for CO oxidation than that prepared by the coprecipitation method. Furthermore, the CeO2-MnOx catalyst with Mn/Ce molar ratio of 1 in the synthesis gel （Ce-Mn-1） exhibited the best catalytic activity, over which the conversion of CO could achieve 90% at 135 ℃. This was ascribed to presence of more Mn species with higher oxida- tion state on the surface and the better reducibility over the Ce-Mn-I catalyst than other CeO2-MnOx catalysts.
基金supported by the National Natural Science Foundation of China under Grant No. 51202103the China Postdoctoral Science Foundation under Grant No. 2012M510789+1 种基金the Natural Science Foundation of Inner Mongolia Autonomous Region under Grant No. 2011BS0804the Program of Higher-level Talents of Inner Mongolia University under Grant No. Z20100123
文摘Nanocomposites of ZnO encapsulated in mesoporous silica were prepared by wetness impregnation and calcination. The samples were characterized by X-ray diffraction, transmission electron microscopy, nitrogen adsorption-desorption isotherms, and X-ray photoelectron spectroscopy. The effects of ZnO content and thermal treatment on the existing form of ZnO as well as phase transformation were investigated. ZnO exists stably in the form of non-crystalline phase or cluster when crystallite size is small. With increasing ZnO content, as the size of ZnO reaches a critical size of crystalline phase, the non-crystalline ZnO or cluster transforms structurally to crystalline ZnO with low energy state. Besides, Zn2Si04 was obtained by solid-state reaction between ZnO and rnesoporous silica. The mesoporous silica acts as not only a reactant but also a diffusion barrier which inhibits the phase transformation from ^-Zn2Si04 to ^-Zn2Si04. The formation temperature of Zn2Si04 is lower than that of conventional solid-state reaction because of the unique structure of mesoporous silica.
基金the National Natural Science Foundation of China(51174101,51464013 and 51404110)Jiangxi Natural Science Foundation of China(20151BAB213011)+1 种基金Education Department Project Fund of Jiangxi Province(GJJ150665,GJJ150648)Key Project of Jiangxi University of Science and Technology(NSFJ2015-K18)~~
文摘Hollow spheres of Si/Al composite oxide with mesopores in the shell wall were prepared by combining O/W/O emulsion with sol-gel process. In this study, TEOS and aluminum isopropylate were used as silicon resource and aluminum resource, respectively. As an additive, PEG-20000 was added into the inorganic precursors. TEM and N2 adsorption-desorption isotherms indicate the presence of mesopores with uniform pore size in the shell wall. The diameter, shell thickness and hollow structure property of the spheres were characterized by transmission polarized light microscopy and SEM. （）27Al MAS NMR spectrum shows that the coordinated number of the aluminum species is four. The influences on special morphology under different oil phase and reaction temperature were also investigated. The hollow spheres exhibit high thermal stability and can remain their intact spherical structures even after calcination at 550 ℃ for 6 h. This strategy can be extended to synthesize hollow spheres of other binary composite oxide with mesopores.
