In this paper,the effects of pore-size of SBA-15 on the adsorption kinetics and equilibrium of large protein molecules Bovine serum albumin(BSA)and lysozyme(LYS)have been investigated.The mesoporous molecular sieve SB...In this paper,the effects of pore-size of SBA-15 on the adsorption kinetics and equilibrium of large protein molecules Bovine serum albumin(BSA)and lysozyme(LYS)have been investigated.The mesoporous molecular sieve SBA-15 with six different pore sizes were synthesized with P123 triblock copolymer as the template agent,and 1,3,5-trimethylbenzene(TMB)and isopropyl alcohol as the pore-expanding agent.The samples were characterized by N2 adsorption/desorption,Scanning Electron Microscopy(SEM),Transmission Electron Microscopy(TEM)and X-Ray Diffraction(XRD).It is found that BSA and LYS were adsorbed rapidly on SBA-15 materials with large pores.The BSA adsorption capacity of sieve with the pore diameter of 21.4 nm reached 500 mg·g-1 within 25 minutes.However,if the pore diameter was smaller than 14 nm,the BSA adsorption capacity of the sieve was only about 220 mg·g-1.The adsorption equilibrium data fits in the Langmuir model,where the coefficient of effective use of specific area of mesoporous molecular sieve was found to be 0.03,0.18,0.37 and 0.48,corresponding to the pore diameter of 10.1 nm,13.2 nm,15.4 nm and 21.4 nm,respectively.The equilibrium loading amount of LYS on SBA-15 materials with pore size of 15.4 nm could be up to 1000 mg·g-1.The coefficient of effective use of surface area of mesoporous molecular sieve with diameter of 3.9 nm,7.4 nm,10.1 nm,13.2 nm and 15.4 nm was 0.10,0.47,0.56,0.71 and 0.79,respectively.It is also noted that greater pore size of mesoporous molecular sieve would lead to a higher coefficient of effective use of surface area.展开更多
Chemical modification(CM)and deposition-precipitation(DP)methods were used for the dispersion of active Au nanoparticles on mesoporous silica materials in this work.XRD,TEM,N2 adsorption isotherms and UV-Vis absorptio...Chemical modification(CM)and deposition-precipitation(DP)methods were used for the dispersion of active Au nanoparticles on mesoporous silica materials in this work.XRD,TEM,N2 adsorption isotherms and UV-Vis absorption spectra were used to characterize in detail Au-SBA-15 materials prepared by the two methods. The analysis results showed that high loading(1.7%,by mass)and uniform Au nanoparticles(approximately 3 nm) were dispersed in the channels of mesoporous SBA-15 by the CM method.While for the DP method,most of Au nanoparticles with the size of 10—15nm were aggregated outside of the channels of SBA-15 and the actual loading of Au was only 0.38%(by mass).展开更多
An inorganic-organic photoluminescence solid material was obtained by immobilizing N-benzylcarbazole compound to an amino-functionalized mesoporous SBA-15（designated as N-benzylcarbazole-amino-SBA-15）.XRD,SEM,and N2...An inorganic-organic photoluminescence solid material was obtained by immobilizing N-benzylcarbazole compound to an amino-functionalized mesoporous SBA-15（designated as N-benzylcarbazole-amino-SBA-15）.XRD,SEM,and N2 adsorption-desorption measurements indicate that the mesostructure of parent material SBA-15 was preserved after introducing amino and N-benzylcarbazole groups.The absorbance and emission studies reveal that the fluorescent N-benzylcarbazole-amino-SBA-15 exhibited red-shift character in comparison to pure N-benzylcarbazole.展开更多
Studies on the effect of the chlorine content of chlorophenols （CPs） on their adsorption from aqueous solution by mesoporous SBA-15 are important in understanding the mechanisms of CP adsorption. In this study, thre...Studies on the effect of the chlorine content of chlorophenols （CPs） on their adsorption from aqueous solution by mesoporous SBA-15 are important in understanding the mechanisms of CP adsorption. In this study, three CPs with different degrees of chlorine content （i.e., 2-chlorophenol, 2,6-dichlorophenol and 2,4,6-trichlorophenol） were investigated. The effects of parameters such as temperature and solution pH were studied. The results showed that CP adsorption by SBA- 15 increased with increasing number of chlorine substituents and depended strongly on the temperature and solution pH. Thermodynamic parameters such as Gibbs free energy change （AGO）, enthalpy change （△H^0） and entropy change （△S^0） were also calculated. By comparison of the adsorption coefficient of CPs with varying physical-chemical properties （size, hydrophobicity and electron density）, we propose that hydrophobic interactions between CPs and the SBA-15 surface, as well as electron donor-acceptor （EDA） complexes between oxygen of the siloxane surface of SBA-15 （e--donor） and the n-system of the CPs （e--acceptor）, were dominant adsorption mechanisms.展开更多
Dielectric barrier discharge(DBD)plasma excited by a high-frequency alternating-current(AC)power supply is widely employed for the degradation of volatile organic compounds(VOCs).However,the thermal effect generated d...Dielectric barrier discharge(DBD)plasma excited by a high-frequency alternating-current(AC)power supply is widely employed for the degradation of volatile organic compounds(VOCs).However,the thermal effect generated during the discharge process leads to energy waste and low energy utilization efficiency.In this work,an innovative DBD thermally-conducted catalysis(DBD-TCC)system,integrating high-frequency AC-DBD plasma and its generated thermal effects to activate the Co/SBA-15 catalyst,was employed for toluene removal.Specifically,Co/SBA-15 catalysts are closely positioned to the ground electrode of the plasma zone and can be heated and activated by the thermal effect when the voltage exceeds 10 k V.At12.4 k V,the temperature in the catalyst zone reached 261℃ in the DBD-TCC system,resulting in an increase in toluene degradation efficiency of 17%,CO_(2)selectivity of 21.2%,and energy efficiency of 27%,respectively,compared to the DBD system alone.In contrast,the DBD thermally-unconducted catalysis(DBD-TUC)system fails to enhance toluene degradation due to insufficient heat absorption and catalytic activation,highlighting the crucial role of AC-DBD generated heat in the activation of the catalyst.Furthermore,the degradation pathway and mechanism of toluene in the DBD-TCC system were hypothesized.This work is expected to provide an energy-efficient approach for high-frequency AC-DBD plasma removal of VOCs.展开更多
A functionalized material, PW/SBA-15m, was prepared successfully in diluted H_2SO_4 aqueous solutions by immobilizing 12-tungstophosphates on chemically modified mesoporous silica SBA-15 and characterized by elemental...A functionalized material, PW/SBA-15m, was prepared successfully in diluted H_2SO_4 aqueous solutions by immobilizing 12-tungstophosphates on chemically modified mesoporous silica SBA-15 and characterized by elemental analysis, FTIR, ~ ~31 P MAS NMR, XRD and TEM. The results indicate that the framework of SBA-15 and the Keggin structure of PW_~12 O^3- _~40 were retained, and that 23%-33%(mass fraction) of ~PW_~12 O^3- _~40 was immobilized; the PW_~12 O^3- _~40 anions were finely dispersed on the pore wall of SBA-15. Having been leached in ethanol at 60 ℃ for 7 h, the loss of PW_~12 O^3- _~40 anions was not found.展开更多
The mesoporous Al-SBA-15 zeolite was obtained via impregnation of pure silica-based SBA-15 zeolite with aluminum nitrate.The Al-SBA-15 sample was calcined in air at 800 ℃ for 6 h and hydrothermally treated at near 1...The mesoporous Al-SBA-15 zeolite was obtained via impregnation of pure silica-based SBA-15 zeolite with aluminum nitrate.The Al-SBA-15 sample was calcined in air at 800 ℃ for 6 h and hydrothermally treated at near 100 ℃ for 120 h,respectively,and then the thermal and hydrothermal stability of Al-SBA-15 sample was investigated by X-ray diffractometry (XRD),scanning electron microscopy (SEM),transmission electron microscopy (TEM) and nitrogen adsorption and desorption techniques.The Al-SBA-15 sample was also studied by 27 Al nuclear magnetic resonance (27 Al NMR) and ammonia temperature programmed desorption (NH 3-TPD) techniques.In addition,the catalytic activity of Al-SBA-15 zeolite was investigated by the Friedel-Crafts reactions of 2,4-di-tert-butylphenol with cinnamyl alcohol.The test results showed that the thermal and hydrothermal stability of Al-SBA-15 zeolite was better than that of SBA-15 zeo-lite.The Al-SBA-15 zeolite sample prepared by impregnation method exhibits more framework aluminum species and Al-O-Si units.Therefore,the number of the surface hydroxyl groups was reduced,resulting in the stabilization of framework structure ofAl-SBA-15 zeolite.The aluminum species can form weak and medium-strong acid sites with catalytic activity.展开更多
A very effective adsorbent for thorium has been obtained by modification of Santa Barbara Amorphous(SBA-15) using the chelating agent thenoyltrifluoroacetone(TTA).The prepared adsorbent(SBA-15-TTA) was characterized u...A very effective adsorbent for thorium has been obtained by modification of Santa Barbara Amorphous(SBA-15) using the chelating agent thenoyltrifluoroacetone(TTA).The prepared adsorbent(SBA-15-TTA) was characterized using scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FT-IR),surface area,porosity,and zeta potential analyses.We investigated the factors affecting Th(IV) adsorption on TTA-SBA-15,such as initial p H,contact time,temperature,and initial metal concentration.The effective initial p H for adsorption was found to be 4.The binding sites on TTA-SBA-15 adsorbent were saturated using an initial Th(IV) concentration of 100 mg L-1.The Dubinin–Radushkevich isotherm suggested a strong chemical interaction between adsorbent and adsorbate.Contact time and temperature had no significant effect on the adsorption.Therefore,the studies show that TTA-SBA-15 is a promising adsorbent to treat Th(IV)-contaminated effluents.展开更多
Hydrothermal liquefaction(HTL)is one of the most promising technologies for conversion of microalgae,and catalysts with high hydrothermal stability are required for controllable HTL.In this article,SBA-15 incorporated...Hydrothermal liquefaction(HTL)is one of the most promising technologies for conversion of microalgae,and catalysts with high hydrothermal stability are required for controllable HTL.In this article,SBA-15 incorporated with transition metals(Ni,Pd,Co and Ru)were synthetized via double-template method for catalytic HTL of microalgae.The results showed that metal incorporated SBA-15 represented high hydrothermal stability at 613 K.The incorporated Ni,Co and Ru was dispersed in SBA-15 enhancing the hydrothermal stability.The catalysts greatly influenced the chemical composition of the obtained bio-oil,which contained a higher percentage of furfural derivatives and a lower content of fatty acids and N-containing compounds,thus bio-oil quality was improved significantly.Higher hydrothermal stability and specific surface areas of Co-SBA-15 contribute to the highest preformation with 78.78%conversion and 24.11 wt%bio-oil yield.Metal incorporated SBA-15 provides a potential application for biomass conversion in high-temperature aqueous phase.展开更多
Mesoporous silica SBA-15 consists of uniform hexagonal, unconnected cylindrical channels with diameters that can be tuned within a range of 1.5 nm-30 nm, and is thought to have a special thermal conductivity. The theo...Mesoporous silica SBA-15 consists of uniform hexagonal, unconnected cylindrical channels with diameters that can be tuned within a range of 1.5 nm-30 nm, and is thought to have a special thermal conductivity. The theoretical investigation of the shell thermal conductivity of the mesoporous silica is performed in the relaxation time approximation in this paper and an available one-dimensional heat transfer model is used to predict the effective thermal conductivity （ETC） of the mesoporous silica. The experimental result of the ETC is also presented for comparison. The shell thermal conductivity of the mesoporous silica decreases with mesochannel radius increasing or wall thickness decreasing, but does not strictly decrease with porosity increasing. The thermal radiation possibly plays a primary role in heat transfer at the large porosity scale. The predicted ETC of SBA-15 with only conduction considered is quite low at the large porosity, even lower than the thermal conductivity of the silica aerogels. To realize it, doping carbon or other matters which can strongly absorb infrared light into SBA-15 is a possible way.展开更多
The production of Ph3Sn–O–SBA-15(Ph3Sn SBA)was achieved by heating triphenyltin chloride and SBA-15in N-methylpyrrolidone at 190°C for 5 h using triethylamine as a catalyst.The composition,structure,and surface...The production of Ph3Sn–O–SBA-15(Ph3Sn SBA)was achieved by heating triphenyltin chloride and SBA-15in N-methylpyrrolidone at 190°C for 5 h using triethylamine as a catalyst.The composition,structure,and surface physical and chemical properties of Ph3Sn SBA were characterized using inductively coupled plasma-atomic emission spectroscopy(ICP-AES),13C,119Sn and29Si solid-state nuclear magnetic resonance(NMR)spectroscopy in situ pyridine infrared spectroscopy(Py-IR),N2adsorption–desorption isotherms,X-ray diffraction(XRD)and transmission electron microscopy(TEM).The results of ICP-AES and organic elemental analysis showed that the grafting yield of Sn was 17%(by mass)for Ph3Sn SBA.The elemental analysis and solid-state NMR results for Ph3Sn SBA were consistent with grafting of triphenyltin on SBA-15.The N2adsorption–desorption,XRD and TEM analyses showed that Ph3Sn SBA retained an ordered hexagonal mesoporous structure,resulting in decreases in the surface area,pore size and mesopore volume,and an increase in acidity as compared with SBA-15.The Hammett acidity function(H0)value and the number of acid sites for Ph3Sn SBA,obtained by the Hammett methods,were 2.77–3.30 and 2.07 mmol·g-1,respectively.The Friedel–Crafts acylation of toluene and acetic anhydride over Ph3Sn SBA was investigated.The yield of methylacetophenone(MAP)and the selectivity for 4-methylacetophenone(PMAP)were 79.56%and 97.12%,respectively,when the conditions were n(toluene):n(anhydride)=2.0:1.0 with 6%(by mass)catalyst,and heating under reflux for 5 h.The PMAP selectivity still reached 93.11%when Ph3Sn SBA was used for the fifth time under the same reaction conditions.展开更多
A series of Ni-W catalysts supported on mesoporous SBA-15 with different Ni:W ratios(NixW/SBA-15, Ni-5%, x=1, 10, 50) was prepared and fully characterized by powder X-ray diffraction(PXRD), Brunner-Emmet-Teller(BET), ...A series of Ni-W catalysts supported on mesoporous SBA-15 with different Ni:W ratios(NixW/SBA-15, Ni-5%, x=1, 10, 50) was prepared and fully characterized by powder X-ray diffraction(PXRD), Brunner-Emmet-Teller(BET), transmission electronic microscopy(TEM), H2-temperature programmed reduction(H2-TPR), and X-ray photoelectron spectroscopy(XPS). High-resolution TEM images, XPS measurements, H2-TPR experiments coupled with PXRD results determined the evolution of Ni and W species. It is found that a trace amount of W from H2WO4 can significantly improve Ni dispersion on SBA-15 (Ni50W/SBA-15) with Ni0 and non-stoichiometric WOx species as small as ca. 3.6 nm. The prepared NixW/SBA-15 was utilized for CO_(2) hydrogenation, which showed that a higher W content restrained the CO_(2) hydrogenation while a lower W ratio promoted both conversion rate and selectivity for methane compared with Ni/SBA-15. The Ni50W/SBA-15 catalyst showed the best performance with a 93.3% CO_(2) conversion rate and 99.7% selectivity for methane at 400 oC under 0.1 MPa and maintained ca. 97% initial performance for 24 h. Tracking product evolution experiments by in-situ Fourier transform infrared spectrascopy(FTIR) indicated that a small amount of W can modify the surface of Ni particles by geometric coverage and electronic modification, which facilitates the adsorption of the CO intermedia and results in the formation of CH4. This work provides a new clue to fabricating efficient CO_(2) conversion bimetallic materials.展开更多
Photocatalysis is one of the most promising methods owing to its great potential to relieve environmental issue. To construct efficient photocatalyst with low energy consumption, mild catalytic conditions, and stable ...Photocatalysis is one of the most promising methods owing to its great potential to relieve environmental issue. To construct efficient photocatalyst with low energy consumption, mild catalytic conditions, and stable chemical properties are highly desired. In this work, a novel, highly active and environmental friendly mesoporous photocatalyst Bi4O5Br2/SBA-15 was synthesized by hydrothermal method, and its characteristics and visible-light catalytic activity were investigated. The synthesized photocatalyst consisted of Langmuir type IV hysteresis loops, which was confirmed to be a composite material with mesoporous structure. It exhibited a high visible-light absorption intensity and a low recombination rate of photo-generated electrons and holes. When the mass ratio of Bi/SiO2 was 30/100 during the synthesis, the obtained photocatalyst (Bi30/SBA-15) reflected the fastest Rhodamine B (RhB) removal rate and achieved 100% decolorization of RhB by both adsorption and degradation process. This high decolorization efficiency can also be maintained and realized by recycling the used composite in practice. The enhanced visible-light photocatalytic activity of novel Bi4O5Br2/SBA-15 photocatalyst can be ascribed to the existing active sites both inside and outside SBA-15 which enhanced the separation of photo-generated electrons and holes.展开更多
基金Supported by the National Basic Research Program of China(2007CB714302)the Outstanding Young Teacher Visiting Scholar Program of Shandong Province
文摘In this paper,the effects of pore-size of SBA-15 on the adsorption kinetics and equilibrium of large protein molecules Bovine serum albumin(BSA)and lysozyme(LYS)have been investigated.The mesoporous molecular sieve SBA-15 with six different pore sizes were synthesized with P123 triblock copolymer as the template agent,and 1,3,5-trimethylbenzene(TMB)and isopropyl alcohol as the pore-expanding agent.The samples were characterized by N2 adsorption/desorption,Scanning Electron Microscopy(SEM),Transmission Electron Microscopy(TEM)and X-Ray Diffraction(XRD).It is found that BSA and LYS were adsorbed rapidly on SBA-15 materials with large pores.The BSA adsorption capacity of sieve with the pore diameter of 21.4 nm reached 500 mg·g-1 within 25 minutes.However,if the pore diameter was smaller than 14 nm,the BSA adsorption capacity of the sieve was only about 220 mg·g-1.The adsorption equilibrium data fits in the Langmuir model,where the coefficient of effective use of specific area of mesoporous molecular sieve was found to be 0.03,0.18,0.37 and 0.48,corresponding to the pore diameter of 10.1 nm,13.2 nm,15.4 nm and 21.4 nm,respectively.The equilibrium loading amount of LYS on SBA-15 materials with pore size of 15.4 nm could be up to 1000 mg·g-1.The coefficient of effective use of surface area of mesoporous molecular sieve with diameter of 3.9 nm,7.4 nm,10.1 nm,13.2 nm and 15.4 nm was 0.10,0.47,0.56,0.71 and 0.79,respectively.It is also noted that greater pore size of mesoporous molecular sieve would lead to a higher coefficient of effective use of surface area.
基金Supported by the National Natural Science Foundation of China （No.20490204）, Shanghai Municipal Science and Technology Commission of China （No.05DJ 14002） and Shanghai Municipal Education Commission of China.
文摘Chemical modification(CM)and deposition-precipitation(DP)methods were used for the dispersion of active Au nanoparticles on mesoporous silica materials in this work.XRD,TEM,N2 adsorption isotherms and UV-Vis absorption spectra were used to characterize in detail Au-SBA-15 materials prepared by the two methods. The analysis results showed that high loading(1.7%,by mass)and uniform Au nanoparticles(approximately 3 nm) were dispersed in the channels of mesoporous SBA-15 by the CM method.While for the DP method,most of Au nanoparticles with the size of 10—15nm were aggregated outside of the channels of SBA-15 and the actual loading of Au was only 0.38%(by mass).
基金Supported by the National Basic Research Program of China(No.2004CB217804)the National Natural Science Foundation of China(No.20673046)
文摘An inorganic-organic photoluminescence solid material was obtained by immobilizing N-benzylcarbazole compound to an amino-functionalized mesoporous SBA-15（designated as N-benzylcarbazole-amino-SBA-15）.XRD,SEM,and N2 adsorption-desorption measurements indicate that the mesostructure of parent material SBA-15 was preserved after introducing amino and N-benzylcarbazole groups.The absorbance and emission studies reveal that the fluorescent N-benzylcarbazole-amino-SBA-15 exhibited red-shift character in comparison to pure N-benzylcarbazole.
基金supported by the Postdoctoral Fund of Southeast Universitythe Natural Science Foundation of Jiangsu Province (No. BK2009294)
文摘Studies on the effect of the chlorine content of chlorophenols （CPs） on their adsorption from aqueous solution by mesoporous SBA-15 are important in understanding the mechanisms of CP adsorption. In this study, three CPs with different degrees of chlorine content （i.e., 2-chlorophenol, 2,6-dichlorophenol and 2,4,6-trichlorophenol） were investigated. The effects of parameters such as temperature and solution pH were studied. The results showed that CP adsorption by SBA- 15 increased with increasing number of chlorine substituents and depended strongly on the temperature and solution pH. Thermodynamic parameters such as Gibbs free energy change （AGO）, enthalpy change （△H^0） and entropy change （△S^0） were also calculated. By comparison of the adsorption coefficient of CPs with varying physical-chemical properties （size, hydrophobicity and electron density）, we propose that hydrophobic interactions between CPs and the SBA-15 surface, as well as electron donor-acceptor （EDA） complexes between oxygen of the siloxane surface of SBA-15 （e--donor） and the n-system of the CPs （e--acceptor）, were dominant adsorption mechanisms.
基金supported by National Natural Science Foundation of China(No.52177130)the Key Projects for Industrial Prospects and Core Technology Research in Suzhou City(No.SYC2022029)。
文摘Dielectric barrier discharge(DBD)plasma excited by a high-frequency alternating-current(AC)power supply is widely employed for the degradation of volatile organic compounds(VOCs).However,the thermal effect generated during the discharge process leads to energy waste and low energy utilization efficiency.In this work,an innovative DBD thermally-conducted catalysis(DBD-TCC)system,integrating high-frequency AC-DBD plasma and its generated thermal effects to activate the Co/SBA-15 catalyst,was employed for toluene removal.Specifically,Co/SBA-15 catalysts are closely positioned to the ground electrode of the plasma zone and can be heated and activated by the thermal effect when the voltage exceeds 10 k V.At12.4 k V,the temperature in the catalyst zone reached 261℃ in the DBD-TCC system,resulting in an increase in toluene degradation efficiency of 17%,CO_(2)selectivity of 21.2%,and energy efficiency of 27%,respectively,compared to the DBD system alone.In contrast,the DBD thermally-unconducted catalysis(DBD-TUC)system fails to enhance toluene degradation due to insufficient heat absorption and catalytic activation,highlighting the crucial role of AC-DBD generated heat in the activation of the catalyst.Furthermore,the degradation pathway and mechanism of toluene in the DBD-TCC system were hypothesized.This work is expected to provide an energy-efficient approach for high-frequency AC-DBD plasma removal of VOCs.
文摘A functionalized material, PW/SBA-15m, was prepared successfully in diluted H_2SO_4 aqueous solutions by immobilizing 12-tungstophosphates on chemically modified mesoporous silica SBA-15 and characterized by elemental analysis, FTIR, ~ ~31 P MAS NMR, XRD and TEM. The results indicate that the framework of SBA-15 and the Keggin structure of PW_~12 O^3- _~40 were retained, and that 23%-33%(mass fraction) of ~PW_~12 O^3- _~40 was immobilized; the PW_~12 O^3- _~40 anions were finely dispersed on the pore wall of SBA-15. Having been leached in ethanol at 60 ℃ for 7 h, the loss of PW_~12 O^3- _~40 anions was not found.
文摘The mesoporous Al-SBA-15 zeolite was obtained via impregnation of pure silica-based SBA-15 zeolite with aluminum nitrate.The Al-SBA-15 sample was calcined in air at 800 ℃ for 6 h and hydrothermally treated at near 100 ℃ for 120 h,respectively,and then the thermal and hydrothermal stability of Al-SBA-15 sample was investigated by X-ray diffractometry (XRD),scanning electron microscopy (SEM),transmission electron microscopy (TEM) and nitrogen adsorption and desorption techniques.The Al-SBA-15 sample was also studied by 27 Al nuclear magnetic resonance (27 Al NMR) and ammonia temperature programmed desorption (NH 3-TPD) techniques.In addition,the catalytic activity of Al-SBA-15 zeolite was investigated by the Friedel-Crafts reactions of 2,4-di-tert-butylphenol with cinnamyl alcohol.The test results showed that the thermal and hydrothermal stability of Al-SBA-15 zeolite was better than that of SBA-15 zeo-lite.The Al-SBA-15 zeolite sample prepared by impregnation method exhibits more framework aluminum species and Al-O-Si units.Therefore,the number of the surface hydroxyl groups was reduced,resulting in the stabilization of framework structure ofAl-SBA-15 zeolite.The aluminum species can form weak and medium-strong acid sites with catalytic activity.
基金supported by the Scientific Technological Research Council of Turkey(No.113Y557)
文摘A very effective adsorbent for thorium has been obtained by modification of Santa Barbara Amorphous(SBA-15) using the chelating agent thenoyltrifluoroacetone(TTA).The prepared adsorbent(SBA-15-TTA) was characterized using scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FT-IR),surface area,porosity,and zeta potential analyses.We investigated the factors affecting Th(IV) adsorption on TTA-SBA-15,such as initial p H,contact time,temperature,and initial metal concentration.The effective initial p H for adsorption was found to be 4.The binding sites on TTA-SBA-15 adsorbent were saturated using an initial Th(IV) concentration of 100 mg L-1.The Dubinin–Radushkevich isotherm suggested a strong chemical interaction between adsorbent and adsorbate.Contact time and temperature had no significant effect on the adsorption.Therefore,the studies show that TTA-SBA-15 is a promising adsorbent to treat Th(IV)-contaminated effluents.
基金National Natural Science Foundation of China(No.21576155 and No.21776159)Research Project of Guangdong Provincial Department of Science and Technology Department(No.2015B020215004)Program for Changjiang Scholars and Innovative Research Team in University(No.IRT13026).
文摘Hydrothermal liquefaction(HTL)is one of the most promising technologies for conversion of microalgae,and catalysts with high hydrothermal stability are required for controllable HTL.In this article,SBA-15 incorporated with transition metals(Ni,Pd,Co and Ru)were synthetized via double-template method for catalytic HTL of microalgae.The results showed that metal incorporated SBA-15 represented high hydrothermal stability at 613 K.The incorporated Ni,Co and Ru was dispersed in SBA-15 enhancing the hydrothermal stability.The catalysts greatly influenced the chemical composition of the obtained bio-oil,which contained a higher percentage of furfural derivatives and a lower content of fatty acids and N-containing compounds,thus bio-oil quality was improved significantly.Higher hydrothermal stability and specific surface areas of Co-SBA-15 contribute to the highest preformation with 78.78%conversion and 24.11 wt%bio-oil yield.Metal incorporated SBA-15 provides a potential application for biomass conversion in high-temperature aqueous phase.
基金supported by the National Basic Research Program of China (973 Program) (Grant No. 2012CB720404)the National Natural Science Foundation of China (Grant No. 50836001)+1 种基金the FOK Ying Tong Education Foundation,China (Grant No. 121055)the Fundamental Research Funds for the Central Universities,China (Grant Nos. FRF-AS-12-002 and FRF-TP-11-001B)
文摘Mesoporous silica SBA-15 consists of uniform hexagonal, unconnected cylindrical channels with diameters that can be tuned within a range of 1.5 nm-30 nm, and is thought to have a special thermal conductivity. The theoretical investigation of the shell thermal conductivity of the mesoporous silica is performed in the relaxation time approximation in this paper and an available one-dimensional heat transfer model is used to predict the effective thermal conductivity （ETC） of the mesoporous silica. The experimental result of the ETC is also presented for comparison. The shell thermal conductivity of the mesoporous silica decreases with mesochannel radius increasing or wall thickness decreasing, but does not strictly decrease with porosity increasing. The thermal radiation possibly plays a primary role in heat transfer at the large porosity scale. The predicted ETC of SBA-15 with only conduction considered is quite low at the large porosity, even lower than the thermal conductivity of the silica aerogels. To realize it, doping carbon or other matters which can strongly absorb infrared light into SBA-15 is a possible way.
基金Supported by the National Science Foundation of Heilongjiang Province(B201010)the Education Department of Heilongjiang Province(12511595)
文摘The production of Ph3Sn–O–SBA-15(Ph3Sn SBA)was achieved by heating triphenyltin chloride and SBA-15in N-methylpyrrolidone at 190°C for 5 h using triethylamine as a catalyst.The composition,structure,and surface physical and chemical properties of Ph3Sn SBA were characterized using inductively coupled plasma-atomic emission spectroscopy(ICP-AES),13C,119Sn and29Si solid-state nuclear magnetic resonance(NMR)spectroscopy in situ pyridine infrared spectroscopy(Py-IR),N2adsorption–desorption isotherms,X-ray diffraction(XRD)and transmission electron microscopy(TEM).The results of ICP-AES and organic elemental analysis showed that the grafting yield of Sn was 17%(by mass)for Ph3Sn SBA.The elemental analysis and solid-state NMR results for Ph3Sn SBA were consistent with grafting of triphenyltin on SBA-15.The N2adsorption–desorption,XRD and TEM analyses showed that Ph3Sn SBA retained an ordered hexagonal mesoporous structure,resulting in decreases in the surface area,pore size and mesopore volume,and an increase in acidity as compared with SBA-15.The Hammett acidity function(H0)value and the number of acid sites for Ph3Sn SBA,obtained by the Hammett methods,were 2.77–3.30 and 2.07 mmol·g-1,respectively.The Friedel–Crafts acylation of toluene and acetic anhydride over Ph3Sn SBA was investigated.The yield of methylacetophenone(MAP)and the selectivity for 4-methylacetophenone(PMAP)were 79.56%and 97.12%,respectively,when the conditions were n(toluene):n(anhydride)=2.0:1.0 with 6%(by mass)catalyst,and heating under reflux for 5 h.The PMAP selectivity still reached 93.11%when Ph3Sn SBA was used for the fifth time under the same reaction conditions.
基金supported by the National Natural Science Foundation of China (No.91961110).
文摘A series of Ni-W catalysts supported on mesoporous SBA-15 with different Ni:W ratios(NixW/SBA-15, Ni-5%, x=1, 10, 50) was prepared and fully characterized by powder X-ray diffraction(PXRD), Brunner-Emmet-Teller(BET), transmission electronic microscopy(TEM), H2-temperature programmed reduction(H2-TPR), and X-ray photoelectron spectroscopy(XPS). High-resolution TEM images, XPS measurements, H2-TPR experiments coupled with PXRD results determined the evolution of Ni and W species. It is found that a trace amount of W from H2WO4 can significantly improve Ni dispersion on SBA-15 (Ni50W/SBA-15) with Ni0 and non-stoichiometric WOx species as small as ca. 3.6 nm. The prepared NixW/SBA-15 was utilized for CO_(2) hydrogenation, which showed that a higher W content restrained the CO_(2) hydrogenation while a lower W ratio promoted both conversion rate and selectivity for methane compared with Ni/SBA-15. The Ni50W/SBA-15 catalyst showed the best performance with a 93.3% CO_(2) conversion rate and 99.7% selectivity for methane at 400 oC under 0.1 MPa and maintained ca. 97% initial performance for 24 h. Tracking product evolution experiments by in-situ Fourier transform infrared spectrascopy(FTIR) indicated that a small amount of W can modify the surface of Ni particles by geometric coverage and electronic modification, which facilitates the adsorption of the CO intermedia and results in the formation of CH4. This work provides a new clue to fabricating efficient CO_(2) conversion bimetallic materials.
文摘Photocatalysis is one of the most promising methods owing to its great potential to relieve environmental issue. To construct efficient photocatalyst with low energy consumption, mild catalytic conditions, and stable chemical properties are highly desired. In this work, a novel, highly active and environmental friendly mesoporous photocatalyst Bi4O5Br2/SBA-15 was synthesized by hydrothermal method, and its characteristics and visible-light catalytic activity were investigated. The synthesized photocatalyst consisted of Langmuir type IV hysteresis loops, which was confirmed to be a composite material with mesoporous structure. It exhibited a high visible-light absorption intensity and a low recombination rate of photo-generated electrons and holes. When the mass ratio of Bi/SiO2 was 30/100 during the synthesis, the obtained photocatalyst (Bi30/SBA-15) reflected the fastest Rhodamine B (RhB) removal rate and achieved 100% decolorization of RhB by both adsorption and degradation process. This high decolorization efficiency can also be maintained and realized by recycling the used composite in practice. The enhanced visible-light photocatalytic activity of novel Bi4O5Br2/SBA-15 photocatalyst can be ascribed to the existing active sites both inside and outside SBA-15 which enhanced the separation of photo-generated electrons and holes.
